Blower motor not working

Hello,

It sounds like the blower motor when out or the relay is having an issue lets use this guide to help test the blower motor and to test the relay. I have included the blower motor wiring diagrams and relay location below.

https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit


Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.

im not sure if the smell is from the motor. yes i do have a multimeter.

then check to see if the blower motor is getting power.......it canbe a ballast resitor ,switch, or the motor itself

Make sure you check it when the blower motor is inop and check the power feed to it and the ground by them self not together.

ok i took apart the blower motor resistor and plug and found the molded end of each melted. not sure if it happened from loose connection or something else?

No it's probably from the blower drawing to much power you should replace it.

Thanks for this post I had this problem and hed to replace the blower motor.

Electrical problem
2006 Chevy Trailblazer 6 cyl Four Wheel Drive Automatic 42k miles

I know the hi blower fan is usually controlled/protected by a seperate fuse or fusible link. My glove box manual makes no reference to this. Where can I find the fuse/fusible link/relay etc that controls the hi blower.
Thx Cory

[quote:6ff119c6eb="ccuneo"]Electrical problem
2006 Chevy Trailblazer 6 cyl Four Wheel Drive Automatic 42k miles

I know the hi blower fan is usually controlled/protected by a seperate fuse or fusible link. My glove box manual makes no reference to this. Where can I find the fuse/fusible link/relay etc that controls the hi blower.
Thx Cory[/quote:6ff119c6eb]

Hi Cory,

The Blower Relay should be located in the Under Hood fuse block.

Also, it usually work the other way around and the only fan speed that works would be the High. However, have you check out the Blower Motor Resistor? it is located under the passenger dash in the duct work near the blower motor.

.

So your saying there is no seperate fuse protecting the hi blower? Seen that for years on GM cars. How exactly do I check out the resistor? any chance of a pic?
Thx Cory

Here is the test proceedure..... You can press your "ctrl" key and the "+" key to zoom in to see if you can read it any better. if you can't let me know and I will email the pics to you...

Here is a pic of the resistor location...

.

2003 Chevrolet Trailblazer. Blower motor not working in all speeds, have already replaced the resistor could it be the switch

OK,
had a warm day today so I decided to test things according to the info in the last post. It turns out if I "jiggle" the multi wire plug that goes into the resistor assembly the hi blower comes on. Doesnt appear to be one of the wires going into the plug but the assembly itself. Can that assembly be replaced by itself or does the whole blower motor have to be changed?
Cory

Could be the blower switch and blower motor itself-

You can replace just the blower resistor there should be only 2 screws holding it in.... here is a pic of the resistor...

.

I have a 2005 trailblazer. It has a front ac/heater fan and a rear one. The had completely quit blowing any air form the ac, heater and defrost. My back one still works fine. Can you please tell me why what may have quit working to cause this? Can you also tell me the part I would need to replace. My warrenty is up by just 6000 miles.

This system, especially if auto temp control, is quite complicated to test even with the right scantool, if you have a warrantee, don't walk, RUN to the shop....

If you cant hear the blower motor, start by checking all fuses.Then use a test light to check for power at the blower motor when it is turned on, in all fan speed positions. If there is power but no blower, then the motor is bad.

Electrical problem
2003 Chevy Trailblazer 6 cyl Four Wheel Drive Automatic

The fan acted strange one day then quit working all together the next. None of the selectable speeds turn on the fan. I checked all the relays and fuses under the hood , nothing was wrong there. With the hood open I turned on the climate control defroster and heard the a/c compressor turn on. What should I do next to find out or narrow the probable failures down.

Place heater fan at hi
disconnect blower motor and check for ground and battery volts at the disconnected wire if you have both remove and replace blower motor
if not suspect blower motor speed resister
Blower Motor Resistor Assembly Located Below right side of dash, near blower motor

The blower did not work when I tried to start the car. I checked to see if it would work in all of the positions (1-5) with no luck. Any recommendations? I would apprecaite any hellp that could save me some money........

Start by checking fuse 35 40A. If it is good, it is your blower motor resistor.

My fan blower does not work on settings 4 and 5 and now only sometimes works on settings 1-3. Although cool air still comes through the ducts.

Subject: EI05082 - Loss of Blower Motor Speeds Except for Low Speed or Inoperative (Replace Blower Motor Resistor and Resistor Module Connector) Models: 2004-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe, TrailBlazer, TrailBlazer EXT 2007 Chevrolet Silverado (Classic) Built Prior to September 1, 2006 2004-2006 GMC Envoy, Envoy XL, Sierra, Yukon, Yukon Denali, Yukon XL 2007 GMC Sierra (Classic) Built Prior to September 1, 2006 with HVAC System AC Front, Manual Temp Control (RPO CJ3) or Heater Only (RPO C42) Supercede: This bulletin is being revised to clarify the Warranty Information. Please discard Corporate Bulletin Number 05-01-38-012B (Section 01 - HVAC). Condition Some customers may comment that the blower will only work on low speeds or has become inoperative. Correction REPLACE THE BLOWER MOTOR RESISTOR AND RESISTOR MODULE CONNECTOR. Replace the blower motor resistor and module connector using the following procedure: Remove the blower fuse. Fullsize Trucks and Utility Vehicles - Htr A/C & HVAC 1 fuses Midsize Utility Vehicles - Blower Fuse 35 located in the Underhood Fuse Block Lower the hush panel or close-out panel enough to gain access to the resistor module connector. Disconnect the connector from the resistor module. Remove the tape from the wiring harness to expose the wiring. Cut the wires back far enough from the connector to eliminate any melted insulation on the wire. Tip Use the old connector as a map for splicing the wires for the new connector. Be sure to use the correct crimping tool from the terminal repair kit J 38125. Use only Duraseal splice sleeves. Other splice sleeves may not protect the splice from moisture or provide a good electrical connection. Install the new connector. Use the yellow splice sleeves provided with the connector. Install new blower motor resistor. Reinstall the fuse or connector block. Test the blower motor to make sure all speeds are functional. Reinstall the hush panel/close-out panel.

follow this info and post back with what you find.

Thanks for sharing this information. I replaced my resistor and resistor connector in under 2 hours - which included driving to the auto part store. The repair cost me $98.00. I am thankful for your site and my mechanical aptitude - it saved me a couple hundred dollars and a bunch of hassle waiting for it at a shop.

2004 trail blazer, when the a/c is running the blower stops running and the abs light and brake light comes on.all of a sudden the blower will start running and the abs light and brake light goes out.

try this ,here is a bulletin for this problem.I know I answered this same problem somewere in the trailblazer section,but here is the bulletin.Diagnose for loss of battery voltage to the rear fuse block on circuit 300 ORN for the following fuses:

Note: Prior to proceeding forward with the information below, it is important to verify the voltage as indicated however it is equally important to verify the integrity of each circuit. This can be achieved by performing a voltage drop test or by adding a device to each circuit that will supply sufficient load to verify the circuits integrity.

HVAC 30A, 4WD 15A, HVAC 1 10A, BRAKE 10A, TBC RUN 3A.

Check circuit 300 ORN for battery voltage when the ignition key is in the RUN position.
Check for battery voltage at the rear fuse block under the rear seat Connector C1 pin D9.
If battery voltage IS NOT present at these locations, check for voltage at the ignition switch pin G for circuit 300 ORN.
If battery voltage IS present at the ignition switch pin G, check circuit 300 for an open.
If battery voltage IS NOT present at the ignition switch pin G, replace the ignition switch.
post back with what you find.

yes I did see this posted earlier. I do not understand what a 300 circuit ORN is. please explain.

circuit 300 is the orange wire that runs from the ignition switch to the rear fuse block.(under the back seat)you are checking for the presents of 12 volts on that circuit.if you have 12 volts than the ign switch is bad,if not you could have a short to ground somewere on that circuit.I would post a picture but it will not let me post one.

you are the man. replaced the ignition switch. everything working fine. thanks so much.

How do you know if it is the resistor or the blower fan? Driving, you can feel the cool air, just not blowing. All 1,2,3,4,5 none of the settings work? First it was the (5) then (1), now the (2,3,4) all went out? Help!

could also be faulty A/C switch. will have to test blower motor by applying 12v power to motor, if it runs then motor is good.

the fan should work fine, under the back seat on the driver side, there is a black box of fuses, the ac fan is call hvac, pull that one is 30 amps and replace. the fan should work just by doing that.

ok. to try the blower motor. there are two bolts that you need to remove, the blower is located just below the brake pedal at the bottom of the truck, is a plastic black motor, is connected to the relay, remove the relay ( is call it air pump relay, about 29.99 at kragen) and then in the opposite side it has the conection, disconnect and run two wires from the batterie, make sure u find a good ground. and if start blowing then is good u may need to replace the relay.

My 2004 Trailblazer has Auto Heat/AC Controls. The blower works sometimes and sometimes not. Sometimes the blower will not come on and and sometimes it comes on but will not turn off even when I shut the car off. Then I have to pull the blower fuse for a few seconds then it will stay off. Once in a while I can play with the Mode, Auto, Blower Speed, Off and Driver Temperature controls and it will start to work or it enables me to shut it off. I believe that it is in the HVAC control unit itself but I am not sure.

I think you are right, the control unit is faulty, or you have a relay that is sticking.

I replaced the blower relay module today. Fixed it right up working correctly again. Thanks!

The blower motor is not working at all, we have replaced fuses and the blower resistor pack, any ideas?

-Check the blower motor control module at lower right side of dash-

blower motor will not work on 1 thru 4 but will work on 5.