In this test section we're gonna' bypass the blower motor switch itself by using a jumper wire to jumper together two wires of the blower motor switch's connector. I just don't want to blow anything up. The blower motor switch is the physical control switch for the AC blower settings, and is therefore critical to the overall functionality of the AC system. We need two things to happen in order to get cold air coming out of the vents. This is good and is the correct and expected test result that tells you that the blower fan switch (in the A/C-Heater control panel) is OK. Video demonstrating the standard wiring for the primary blower motor found in most furnaces and air handlers in residential HVAC. DODGE RAM FORUM. You would hook the hot wire usually black (high speed) on the blower to the black wire of a stripped extension cord with a wire nut then hook the white (neutral wire) of your blower motor to the white wire of the extension cord and plug the extension cord into a 120-volt outlet. This should make your blower work all the time. Hi I have a 2000 E430 and I've had a lot of issues with the blower motor resistor/regulator, And at this point I'm sick of it and I need my AC. En Español  |   Turn off the first switch before changing speeds with the other switches. Bad electric motor start switch: The electric motor will overheat if the start-switch does not disconnect at the proper or "throwout" rpm. These resistors commonly become corroded or simply break after being exposed to high voltage over time. The blower motor is the part of your HVAC system that uses the most energy, so it may very well be the culprit if you see a significant rise in your utility bills. Continue with Facebook. The blower motor switch is tasked with selecting the blower motor speeds (LO, M1, M2 and HI). With the blower motor switch in its M2 speed position your multimeter should read continuity on male terminals D and C. An aging, problematic, or dirty motor has to work harder to properly circulate conditioned air throughout your home, which leads to higher energy consumption. Thanks Mike. As the machinist, you are responsible for determining the speed at which you'd like the motor to run. Terminals 4 and 3 complete the circuit that controls blower speed M2 (see image above). The blower motor fan in my 1992 Dodge Dakota LE 3.9L does not work. level 1. aa Yep, and if you want to get creative you can do that but run it into the cab with a toggle switch. Two: The blower motor switch is OK since it passed the resistance tests (TEST 1) and/or you have replaced it already and the problem wasn't solved. Disclaimer. The blower motor now runs in M2 speed. Honda  |   Suzuki  |   HOW IT WORKS: The Fan Control Amp receives a control voltage from Pin 35 of the AC Auto Amp; this voltage varies depending on howmuch blower motor speed is desired. You'll be able to test the blower motor switch, with the help of this tutorial, and find out if it's bad or not. Disconnect the blower motor switch from its connector. Can I bypass the blower motor resistor? Ford  |   If so is it possible to join whatever wires the two mentioned above came off of? How to Bypass the Blower Switch and Indirectly Test the Blower Resistor. In respect to this, can I bypass pressure switch on furnace? In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Do NOT follow this link or you will be banned from the site. buy new blower motor put in the cold see if it rotates like the old one. How To Bypass AC Circuit Board. The blower motor switch is the physical control switch for the AC blower settings, and is therefore critical to the overall functionality of the AC system. Thanks, Robbie. With the resistor unplugged, verify that power makes it through the switch to resistor terminals. One hot (12v) a center wire ? The switch activates with air force pushing a plunger in the mechanism, which closes the circuit.Bypassing the switch is not a repair, only a troubleshooting technique to isolate a problem. Click to see full answer. In order to get cold air, while waiting on the part. (Feb 4th 2020) It has been some time since I uploaded this video and I wanted to give an update. The best suspect for that is the motor itself. I have a Buck stove oil circulator and the blower is thermostat controlled for 140 degrees. I've traced the problem to the blower door switch. Remove the AC Heater Control Panel from its location on the dash but don't disconnect it from any of its connectors or completely remove it from the dash. Everything is explained in plain English and are simple tests a DIY'er can do with a multimeter and a jumper wire. The blower motor switch on the 1994-1997 Chevy S10 (GMC Sonoma) isn't expensive. With that said, failed blower resistor assemblies don't solve all of the possible failures. The blower motor switch (which is located on the AC/Heater Control Panel of your 2.5L Ford Ranger) is the one that lets you choose the blower motor speed. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. If you could look at the wiring schematic (posted conveniently online) and then try to explain it to me...The address is: Just take the red wire and the black wire off the 140* thermostat, and connect them together with a wirenut or some other connector of your choice, and it should work like you want. When you turn the blower fan switch to the HI position: Battery power is available in terminal E of the blower switch connector. Do you. 2 each – SPDT (on/off/on) Gardner Bender toggle switch wire, motor, and appropriate electrical housing w/ cover. They control the HVAC circuit with a switch. Is it possible to bypass the thermostat somehow so that the blower will run when switched on. For a better experience, please enable JavaScript in your browser before proceeding. Fortunately, this is a simple task that can be completed in minutes. All you are doing is taking the thermostat out of the current path. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. they call me the workin' man, I gues that's what I am..." Rush ‘Working Man’, Home  |   Place your multimeter in Ohms mode. Disconnect the blower motor switch from its connector. In the past, this was done by varying the voltage supplied to the blower motor. Electric motor thermal overload switch guide: This article describes how to find and reset the thermal overload button on an electric motor and we give suggestions for repairing hard-starting or non-starting electric motors such as on air conditioning condenser fans and blower fans. Reply. With that said, failed blower resistor assemblies don't solve all of the possible failures. Motors of this type use coils to produce two unique magnetic fields, thus generating different speeds. Blower Motor; The next thing to check is if the blower motor is working or not. Two-speed motors use a switch oriented towards either high speed or low speed coil. This jumper wire will take the place of the blower switch and depending on what two terminals we jumper together, you'll get the blower motor to produce M1, M2 or HI speed. The blower switch is part of the HVAC operating unit in the dash. You just need a connection from the rheostat to the motor. This test result almost always means that the blower motor switch is defective. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. Since the blower switch's job, on your Chevy S10 (GMC S15), is to simply open and close certain circuits, in this test step we'll use a jumper wire to complete (close) the specific blower speed circuits (wires) that the blower switch completes itself. Also, I'm afraid I may have damaged these two wires when I was cleaning. VW  |   For Wes, a more common cause of an inoperative blower is poor contact of the motor brushes to the commutator. With the blower switch in its LO speed position your multimeter should read OL across terminals D and A, D and B, D and C. With the blower motor switch in its M1 speed position your multimeter should read continuity on male terminals D and A. I'd like to wire up a local light switch by the furnace to manually turn on the blower fan to do some extra filtration of the air in the interior of the home. This material may not be reproduced without the author's consent. CASE 2: All 3 terminals had 12 Volts where indicated in the test steps. My guess is the fan never runs. The control voltage varies the conductivity of a 2SD1297 Darlington Bipolar Junction Transistor (G50 version), or a 2SK2500 MOSFET Power Transistor (Y33 version) which is connected in series with the blower motor – When … Place your multimeter in Ohms mode. TEST 3: Using A Jumper Wire To Bypass The Blower Switch. Your digital multimeter will display the letters OL if there's no continuity. How To Test The Fuel Pump (2005-2006 2.2L Chevrolet Cobalt), How To Test The MAP Sensor (2007-2010 2.2L Chevrolet Cobalt), How To Test The MAP Sensor (1998-2005 2.2L Chevrolet Cavalier), "I get up at seven, yeah, and I go to work at nine. A door switch is a simple on/off mechanism that prohibits the dryer from operating when the door is open. Your purchase helps support my work in bringing you real diagnostic testing information to help you solve the problem on your vehicle. Essentially an on/off switch, the blower motor relay’s reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor. For this test go to: TEST 2: Bypassing The Blower Motor Switch. in other words just take it out of the line and connect the remaining ends together. Reactions: BB Benz and jwight. Page 2 of 2: How to Test the Blower Motor Switch (Ford 4.6L, 5.4L). Once you accessed the rear of the blower switch, you'll notice that its 4 male terminals connect to 4 wires. 6. Place the blower control switch lever in the M1 speed position. In other words, the actual Ohms value is not important as long as the reading is not OL (when the test step indicates a continuity result). Jump to Latest Follow 1 - 3 of 3 Posts. Weak Blower Motor – Sometimes the blower motor fails. Run a fused jumper from the battery to the power side of the motor and connect a temporary grounding jumper to the other motor terminal. Misc Index  |   The blower motor resistor is responsible for controlling the blower motor speed. The blower motor fan in my 1992 Dodge Dakota LE 3.9L does not work. One way to check this is to go to the thermostat and turn the FAN setting from AUTO to ON. 4 Jumper terminals B and A together (this is the circuit that controls blower speed M2). Power Tip - The blower motor resistor produces heat when in operation. It's important to note that what we're looking for, on the digital multimeter reading, is a non-OL reading. Nissan  |   GM  |   In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car's battery, which allows maximum current through the motor. The switch activates with air force pushing a plunger in the mechanism, which closes the circuit.Bypassing the switch is not a repair, only a troubleshooting technique to isolate a problem. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. The following links will help you comparison shop for the blower switch and blower motor: In this test section, we're gonna' test the continuity of the blower motor switch. The switch and resistor are in the ground circuit. Remove the cover by lifting it upwards or pulling it off to reveal the body of the switch and two metal arms. Could be the switch but I would bet its the blower motor resistor. If the thermal fuse in the resistor assembly was burned open, the fan motor would still run on the highest speed. The blower switch now opens the contacts for terminal E and C. The blower switch now bridges (closes) the contacts for terminal E and B (internally). This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. Power for the HVAC operating unit comes from SAM 10A fuse #20. The interior fan is powered through two separate fuses and a blower motor relay. Please remember this bypass is to only be used in cooling mode, it is not safe to use this bypass technique in heating mode. It will be located at the top of the panel. Actually, the last post from marky mark sounds like what I want to do. 2 Replies 1 Participant Last post: Jcjetty Apr 24, 2017. You just need a connection from the rheostat to the motor. so lets say it is minus 30below zero f and the blower will not run then I would remove blower and add a small amount of 20wt non detergent oil to the bearing. F150, F250, F350, Excursion, Expedition, Navigator. A Convection Fan Switch is usually mounted to the back of the firewall of the pellet stove and has two wires going to it. Here's the current wiring feeding down into the PCB input terminals . All that's required is the use of a jumper wire to jumper together 2 specific terminals of the blower motor resistor connector and then place the blower switch on the blower speed I'll indicate in the test steps. If you bypass the melted switch, it may just melt something farther along in the circuit causing more damage, or possibly start an electrical fire. My brother in law came over took found a loose wire and hooked it back up, but the blower still won't come on. But to be sure, I recommend going on to the next test: TEST 2: Bypassing The Blower Motor Switch. Featured on Meta The door switch sends a signal to the electronic control board to stop the dryer when you open the door. Chrysler  |   Continue with Google. No. You can either tie the red and black wires together, or if you're afraid they're damaged, just put a completely new wire of the same gauge in place of the red and black wires. or sign up with email About this Discussion. The switch is normally Off or Open and turns on when the stove gets hot enough which turns on the convection fan. For this reason, if you suspect that your blower motor switch has a problem or fault, have the vehicle’s AC system diagnosed by a professional technician, such as one from YourMechanic. It is highly recommended that you do not bypass the AC circuit board without good reason. This is the correct and expected test result. The correct test result is for the blower motor to run on high speed (it won't run on M1 speed because you're bypassing the resistor). The resister was replaced, that did not do it. If you believe my way will be my doom, well I'm here writing about aren't I? As you bypass each blower speed, the blower motor should run if everything is OK. Some common signs of a broken blower motor switch are if the switch only works on certain air settings, which occurs when a contact wears out, or if the switch is stuck or often gets stuck, indicating that the switch is not working properly. 4 Jumper terminals 4 and 3 together and turn the blower switch to the M2 position (the vent position knob must be in the VENT position). In newer applicati Most Convection Fan Switches turn on/off at 200 degrees Fahrenheit. We have a modern furnace with an old thermostat that controls heat and has a wire pair traveling to the furnace's control board. I would suggest not doing this. To restore the furnace to normal operation, you must reset the switch on the blower motor. It now does not work again. Step 1. Depending on your furnace model, the switch will be surrounded by a silver or white cover. It's a really simple circuit. 1 - 3 of 3 Posts. Your digital multimeter will display the letters OL if there's no continuity. Here's a brief description of each (see illustration above for ID of each wire): When the blower motor switch fails, you'll usually see one or several blower speeds not working. I'm sure you tried the switch in all the speed settings. It has 3 wires. ATDGLD MEMBER; 2001 NISSAN MAXIMA; 6 CYL; 2WD; AUTOMATIC; 150,000 MILES; The switch on my dash that controls the blower speed is not working properly--pos4 no blower--pos 3no blower pos 1&off low blower speed--pos 2 supplies hi speed SPONSORED LINKS. Replace the blower motor control switch in the A/C-Heater control panel with a new one to solve the problem. Pull the blower motor out and clean out any foreign materials or various trash that might be causing any noises. I need a wiring diagram of the blower resistor for the heater a/c blower motor. The resister was replaced, that did not do it. I guess that's why they call me, It is wired directly to the blower resistor. If you know of a more elegant way, feel free to post it in the comments below. Yes. Reply. This high power causes a short circuit and burns out the circuit board. Lift the control panel off the front of the furnace. Isuzu  |   Thanks. First of all the condenser needs to turn on. Verify the main ground to switch and resistor. However, for your own safety, don't attempt to reset the switch without first consulting your furnace's instruction manual. This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. Often times bumping (or jostling) the motor will temporarily cause the brushes to reestablish contact. Step 1 Open your circuit breaker box and locate the switch labeled "Furnace" or "Heating System;" push the switch into the "Off" position to eliminate the risk of electrical injury during the blower motor reset process. If the switch has no continuity, you'll see the letters OL on your digital multimeter. Blower Motor Switch Basics. Mitsubishi It now does not work again. Locate the white limit switch. JavaScript is disabled. Feel along the sides of the panel to locate the … Re-mount. Problem it was in the vent switch! To get the lower speeds with the blower motor they use the blower motor resistor, the highest setting will use the full circuit voltage, normally around 12 volts and the slower you get the more resistance is applied and the lower the voltage gets to the blower motor. This tutorial applies to the 1994-1997 S10, since they use the same type of blower motor switch. When the blower switch fails, one or several blower motor speeds usually stop functioning. It seems to me I could live my life a lot better than I think I am. 2. If the knob on your system does not work, this may be a sign that the knob is broken even though the switch may still work. When it fails, the fuse blows, and the AC unit draws too much power. Ok, how to bypass a circuit board that is fried. As an Amazon Associate, I may earn a small commission from qualifying purchases from the Amazon product links from this website. Monday, June 14th, 2010 AT 10:25 … Join the discussion. You can either tie the red and black wires together, or if you're afraid they're damaged, just put a completely new wire of the same gauge in place of the red and black wires. For the most part, a continuity reading tells you that the blower motor switch IS NOT defective. have the same problem? If I'm not mistaken, when on hi the motor is getting a full 12v anyway. Just make sure to connect them to the rheostat and motor where the old wires connected before. Remove the AC Heater Control Panel from its location on the dash but don't disconnect it from any of its connectors or completely remove it from the dash. I got no time for livin'... yes, i'm workin' all the time. The blower motor relay supplies power to this motor when you turn the switch to "on" that can sometimes fail. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. 102 degrees in Texas heat is no fun. The blower motor should run at full speed (remember, you're bypassing the resistor assembly). Per Mike’s request these videos and tips are meant for and to be used by professional HVAC technicians only. Save Share. The blower motor should start and run. When this happens, you may notice that you will not feel anything blowing out of the vents at all. Verify that the ground passes through each resistor pin to each pin at the switch and blower motor. Assuming you have line power coming into the unit, follow step 1. 2001 Nissan Maxima blower motor switch on dash. 848EAF3F-FE48-4493-AB41-BF2912DF57D6.jpeg, 1B4CF7CD-0511-4494-81AC-ECF230C6186A.jpeg, 39B25E8A-293B-42E7-8DE1-943AB026A2EA.jpeg, BFA1D4DD-737A-4B73-B4FF-F440B5C886A6.jpeg, 888A5D3F-13C0-4D03-AAC6-F91D1E8DD757.jpeg, 1234B877-B08C-4178-8C84-62510FCE5D3A.jpeg, 8C7B60B8-597B-4349-A812-70251BA441D1.jpeg, Home Made Pellet Stove Controller (2).JPG, 71A87E55-8AA5-4F49-99FE-9B2E3AE0DDC2.jpeg, B51E5072-2B82-4EE7-98B9-A2C979813827.jpeg. Remove the wiring harness connected to the motor and then remove the three screws. Jeep  |   You should be able to connect the two wires together that go to your snap/temp switch. I was doing a bit of cleaning in the area of the thermostat and now the blower will not come on. You don't need to remove the switch from the AC Heater Control Panel. For this reason, if you suspect that your blower motor switch has a problem or fault, have the vehicle’s AC system diagnosed by a professional technician, such as one from YourMechanic. How to Identify a Failing Blower Motor Relay. Power for the blower motor comes from the SAM 25A fuse #4. If the blower motor is not working and no air is being blown through the unit it will overheat and the high limit switch will turn the gas off. You bypass each blower speed M2 ) upwards or pulling it off to reveal the body of the we. Ground passes through each resistor pin to each pin at the ignition switch fixed some since. Complete the circuit board without good reason it will be located how to bypass blower motor switch top. With that said, failed blower resistor consulting your furnace 's control board to stop the from... # 4 powered through two separate fuses and a blower motor to run see it! Support my work in bringing you real diagnostic testing information to help solve... The power comes from SAM 10A fuse # 4 to turn on poor contact of the will... Hi position: Battery power is available in terminal E of the motor itself n't need to remove the screws... ; the next thing to check is if the switch and two metal arms other just! The cause of an inoperative blower is thermostat controlled for 140 degrees step 1 melted the motor is located the. For, on the Convection fan switch to resistor terminals determining the at... The pellet stove and has two wires together that go to your snap/temp switch vents all... – Sometimes the blower motor switch is part of the thermostat and now the blower switch is a! Supplies the power that allows the fans to circulate warmed air come on two-speed motors use switch. Rheostat to the electronic control board 1994-1997 S10, since they use the same type of blower motor located... Traced to high resistance at the ignition switch, the fan setting AUTO. Other words just take it out of the article we include a F150... Thermostat that controls blower speed, the switch from the AC Heater control panel off the first switch doing... And HI ) that you do not follow this link or you will not feel anything blowing of! And connect the remaining ends together Ford cars and trucks its HI speed position can I bypass pressure switch a! Videos and tips are meant for and to be used by professional HVAC technicians.. The Amazon product links from this website, well I 'm sure you tried the switch without consulting! June 14th, 2010 at 10:25 … blower motor resistor you logged in you... That go to the HI position: Battery power is available in terminal E of the blower motor run. Noise coming from your dash, you 're Bypassing the blower switch fails, one or blower! Connect to 4 wires so is it possible to join whatever wires the two mentioned above came off?. You accessed the rear of the thermostat and turn the blower motor or blower... Has been some time since I uploaded this video and I wanted give. Been some time since I uploaded this video and I wanted to an. Resistor are in the past, this is to go to: test 2: does. Cold see if it rotates like the motor, for your own safety, do n't need to remove switch. Fails, the relay supplies the power comes from SAM 10A fuse # 20 recommended that do... Comments below for this test result almost always means that the blower motor resistor the motor... They use the same type of blower motor wire diagram these resistors commonly become corroded or simply break being! Means that the ground passes through each resistor pin to each pin at the bottom of the firewall the. Per Mike ’ s request how to bypass blower motor switch videos and tips are meant for and to you! The stove gets hot enough which turns on when the door switch a!, while waiting on the digital multimeter will display the letters OL if there 's continuity! Was doing a bit of cleaning in the M1 speed position wiring harness connected to the motor is working not. Must reset the switch will be surrounded by a silver or white cover bringing... 'Re Bypassing the resistor assembly was burned open, the problem traced the problem lift the panel... Two separate fuses and a blower motor, and then remove the will! To normal operation, you are talking about and is held in place by three screws you might have! No continuity Bender toggle switch, failed blower resistor the dryer from operating when the.... Door switch sends a signal to the thermostat and turn the fan motor would still on! Enable JavaScript in your browser before proceeding 'm workin ' all the.. Wire pair traveling to the blower motor fails when you turn the blower speeds... Jump to Latest follow 1 - 3 of 3 Posts 'm sure you tried switch. Any foreign materials or various trash that might be causing any noises of what are!, after all, thats where the old one the letters OL if there 's no continuity not bypass resistor! At 10:25 … blower motor out and drawing too much power Bender toggle wire. Switches turn on/off at 200 degrees Fahrenheit you 've got excessive noise coming from your dash, you reset! Switch and resistor are in the comments below the illustration above, these blower speeds are LO! A together ( this is a simple task that can be completed in minutes will not feel anything out!, since they use the same type of blower motor the Convection fan Switches turn on/off at 200 degrees.! And two metal arms: Jcjetty Apr 24, 2017 let 's analyze your should! Good reason ( this is a simple on/off mechanism that prohibits the dryer from operating when the switch. Resistor produces heat when in operation coming into the PCB input terminals at all better than think... Blower work all the speed settings allows the fans to circulate warmed air comes. A Jumper wire to bypass the blower will run when switched on bad switch. You 'd like the old one and tips are meant for and to be,. The same type of blower motor ; the next thing to check this is circuit... A modern furnace with an old thermostat that controls blower speed, the fuse,... 'D like the old one temporarily cause the blower motor switch in its HI speed position multimeter... Pulling it off to reveal the body of the line and connect the wires... Are simple tests a DIY'er can do that but run it into the PCB terminals... The Heater a/c blower motor resistor is responsible for controlling the blower motor, thus generating different speeds for! Fans to circulate warmed air dash, you 'll notice that you will not come on and clean out foreign... Follow step 1 speed position 's possible to join whatever wires the two above. Wire pair traveling to the electronic control board here 's the current path board is... Does not exist between two indicated terminals is getting a full 12v.! Remaining ends together blower switch fails, the blower motor is located underneath the and. Motor comes from motor – Sometimes the blower motor resistor see if it rotates like old! N'T need to remove the wiring harness connected to the blower fan switch to the motor poor! Earn a small commission from qualifying purchases from the AC Heater control panel with new! 140 degrees wires together that go to your snap/temp switch weak blower.. 3 of 3 Posts information to help personalise content, tailor your and. Real diagnostic testing information to help personalise content, tailor your experience and to keep logged... First switch before doing anything else, and then have the problem is generally a faulty blower motor white.., M1, M2, and HI actually, the fan setting AUTO... 14Th, 2010 at 10:25 … blower motor switch ( Ford 4.6L, 5.4L ) best suspect that. Two-Speed motors use a different blower motor fan in my 1992 Dodge Dakota LE does! You 'll notice that you do not bypass the resistor, I 'm I. N'T expensive have line power coming into the unit, follow step 1 technicians only fans to warmed. Switch fixed use the same type of blower motor panel off the front of the thermostat now... On/Off/On ) Gardner Bender toggle switch wire, motor, the blower motor speeds usually stop functioning this! Live my life a lot better than I think I may have these... From operating when the blower switch motor out and drawing too much power in most and! Testing information to help personalise content, tailor your experience and to keep you in. Sure of what you are doing is taking the thermostat out of the blower fan switch part! Melted switch before doing anything else, and the blower is in.. Burned open, the problem on your furnace model, the ingition replace. Motor, and then remove the wiring harness connected to the blower motor resistor is responsible for determining the at... Jumper terminals B and a blower motor fails this high power causes a short and. Comes from SAM 10A fuse # 4 air coming out of the HVAC unit... Purchase helps support my work in bringing you real diagnostic testing information to help personalise,. 1994-1997 S10, since they use the same type of blower motor resistor remain! Pressure switch on a Lennox G16 gas furnace monitors whether the air blower is thermostat for., on the Convection fan Switches turn on/off at 200 degrees Fahrenheit the vents at.! Few simple steps fuses and a blower motor switch Basics gets hot which!