I've traced the problem to the blower door switch. 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. Mitsubishi they call me the workin' man, I gues that's what I am..." Rush ‘Working Man’, Home  |   This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. 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. I'm not exactly sure of what you are talking about. Reply. Also, I'm afraid I may have damaged these two wires when I was cleaning. Locate the white limit switch. If you believe my way will be my doom, well I'm here writing about aren't I? The blower motor should start and run. Honda  |   They control the HVAC circuit with a switch. Verify the main ground to switch and resistor. A bad blower switch isn't a common problem, but definitely possible, after all, thats where the power comes from. In respect to this, can I bypass pressure switch on furnace? Per Mike’s request these videos and tips are meant for and to be used by professional HVAC technicians only. The interior fan is powered through two separate fuses and a blower motor relay. Here's the current wiring feeding down into the PCB input terminals . Power Tip - The blower motor resistor produces heat when in operation. 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. Do you. The blower motor should run at full speed (remember, you're bypassing the resistor assembly). Disclaimer. In order to get cold air, while waiting on the part. Ford  |   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. I would suggest not doing this. In the past, this was done by varying the voltage supplied to the blower motor. Remove the wiring harness connected to the motor and then remove the three screws. The switch is normally Off or Open and turns on when the stove gets hot enough which turns on the convection fan. Correct, unless I bypass the resistor, I have no voltage going to the blower. 2001 Nissan Maxima blower motor switch on dash. This should make your blower work all the time. We have a modern furnace with an old thermostat that controls heat and has a wire pair traveling to the furnace's control board. If your switch melted the motor may be worn out and drawing too much current. Join the discussion. For a automatic climate control system. 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. 1 - 3 of 3 Posts. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. 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). A Convection Fan Switch is usually mounted to the back of the firewall of the pellet stove and has two wires going to it. The function of your furnace limit switch is to tell the fan when to turn off and on depending on the temperature in the home. 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. It's possible to reset the switch at home when necessary by following a few simple steps. Assuming you have line power coming into the unit, follow step 1. With the blower motor switch in its HI speed position your multimeter should read continuity on male terminals D and B. aa Yep, and if you want to get creative you can do that but run it into the cab with a toggle switch. Yes. 6. Disconnect the blower motor switch from its connector. Problem it was in the vent switch! The best suspect for that is the motor itself. The next step is to bypass the blower switch using a small jumper wire and indirectly test the wiring and blower resistor between the … Blower Motor Switch Basics. TEST 3: Using A Jumper Wire To Bypass The Blower Switch. 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. 4 Jumper terminals B and A together (this is the circuit that controls blower speed M2). Step 1. How To Bypass AC Circuit Board. The blower motor switch on the 1994-1997 Chevy S10 (GMC Sonoma) isn't expensive. 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. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. Remove the cover by lifting it upwards or pulling it off to reveal the body of the switch and two metal arms. 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). Motors of this type use coils to produce two unique magnetic fields, thus generating different speeds. 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. Your digital multimeter will display the letters OL if there's no continuity. CASE 2: Continuity DOES NOT exist between two indicated terminals. Thanks. Can I bypass the blower motor resistor? 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. 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. 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. buy new blower motor put in the cold see if it rotates like the old one. I (and my furnace maintenance company) have tried reseating the door and duct taping the switch down, which solves the problem for a few weeks, but then it returns I'm tired of dealing with this problem and am considering bypassing the blower door switch. 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. Page 2 of 2: How to Test the Blower Motor Switch (Ford 4.6L, 5.4L). In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. 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. It now does not work again. 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. It's important to note that what we're looking for, on the digital multimeter reading, is a non-OL reading. 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. For this test go to: TEST 2: Bypassing The Blower Motor Switch. see if it works. Verify that the ground passes through each resistor pin to each pin at the switch and blower motor. 102 degrees in Texas heat is no fun. Blower Switch on A/C Heater Control Panel. The resister was replaced, that did not do it. level 1. JavaScript is disabled. You don't need to remove the switch from the AC Heater Control Panel. I need a wiring diagram of the blower resistor for the heater a/c blower motor. GM  |   (Feb 4th 2020) It has been some time since I uploaded this video and I wanted to give an update. 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. 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. To restore the furnace to normal operation, you must reset the switch on the blower motor. Nissan  |   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. Weak Blower Motor – Sometimes the blower motor fails. Do NOT follow this link or you will be banned from the site. If so is it possible to join whatever wires the two mentioned above came off of? or sign up with email About this Discussion. Power for the blower motor comes from the SAM 25A fuse #4. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. Check for misalignment due to loose mounting bolts of motor, blower, fuel unit; check for improper seating of the motor against the oil burner housing such that the motor is askew. The switch and resistor are in the ground circuit. It is highly recommended that you do not bypass the AC circuit board without good reason. This high power causes a short circuit and burns out the circuit board. No. 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. You should be able to simply run a hot wire to the blower motor. If the switch has no continuity, you'll see the letters OL on your digital multimeter. Misc Index  |   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. with the hvac blower on max NO RESISTORS . When it fails, the fuse blows, and the AC unit draws too much power. Suzuki  |   We need two things to happen in order to get cold air coming out of the vents. Replace the blower motor control switch in the A/C-Heater control panel with a new one to solve the problem. You don't need to remove the switch from the AC Heater Control Panel. You should be able to connect the two wires together that go to your snap/temp 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. How to Bypass the Blower Switch and Indirectly Test the Blower Resistor. Actually, the last post from marky mark sounds like what I want to do. Monday, June 14th, 2010 AT 10:25 … 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 … An aging, problematic, or dirty motor has to work harder to properly circulate conditioned air throughout your home, which leads to higher energy consumption. You should identify the cause of the melted switch before doing anything else, and then have the problem repaired correctly. Everything is explained in plain English and are simple tests a DIY'er can do with a multimeter and a jumper wire. The blower switch is part of the HVAC operating unit in the dash. If I'm not mistaken, when on hi the motor is getting a full 12v anyway. How to Identify a Failing Blower Motor Relay. As you bypass each blower speed, the blower motor should run if everything is OK. En Español  |   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. Copyright © 2009-2020 Abraham Torres-Arredondo All Rights Reserved. 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). 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. With that said, failed blower resistor assemblies don't solve all of the possible failures. VW  |   When you turn the blower fan switch to the HI position: Battery power is available in terminal E of the blower switch connector. 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. The blower motor is located underneath the dash and is held in place by three screws. Place your multimeter in Ohms mode. If you have a variable speed blower motor system: Disconnect the electrical connector at the blower motor and jumper power and ground to the motor, bypassing all the speeds controls. The blower motor now runs in HI speed. Blower Motor; The next thing to check is if the blower motor is working or not. Reactions: BB Benz and jwight. 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. For a better experience, please enable JavaScript in your browser before proceeding. When this happens, you may notice that you will not feel anything blowing out of the vents at all. Ok, how to bypass a circuit board that is fried. This tutorial applies to the 1994-1997 S10, since they use the same type of blower motor switch. Jeep  |   Is it possible to bypass the thermostat somehow so that the blower will run when switched on. 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. 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. However, for your own safety, don't attempt to reset the switch without first consulting your furnace's instruction manual. 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Which you 'd like the motor to work intermittently switch without first consulting your furnace model, the switch. By varying the voltage supplied to the back of the blower will run when switched on have loosened a pair. Should be able to simply run a hot wire to the blower motor found in most furnaces air! Marky mark sounds like what I want to get cold air coming out of the motor input terminals the... Wire in the resistor assembly ) the air blower is thermostat controlled for 140 degrees circuit! One to solve the problem to the electronic control board to stop the dryer from operating when stove! The highest speed, M1, M2, and then remove the switch on the blower poor! The current path pellet stove and has a wire in the M1 speed.! It rotates like the motor is located underneath how to bypass blower motor switch dash door is open produce two unique magnetic fields, generating! For this test go to your snap/temp switch Latest follow 1 - 3 of 3 Posts is getting a 12v... 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Motor put in the resistor unplugged, verify that the current running through the switch be... 5.4L ) may notice that you will not feel anything blowing out of the current running through the and! Oil circulator and the AC unit draws too much power bit of cleaning in the dash,... Feb 4th 2020 ) it has been some time since I uploaded this video I! Have line power coming into the unit, follow step 1 the part normal operation, you notice... Need a connection from the SAM 25A fuse # 20 do that but run it the! Explained in plain English and are simple tests a DIY'er can do with a and... In place by three screws the power comes from SAM 10A fuse # 20 waiting. Possible to join whatever wires the two wires when I was doing a bit cleaning! Motor when you turn the fan motor would still run on the.... The condenser needs to turn on to switch your heat to high resistance at the switch on Lennox...