Air Conditioning/Blower not working

Have the blower fan motor checked. Looks like it is failing. Try giving thr blower motor housing some banging with your hands and if it starts working, the motor is due for replacement. Get this done and monitor if the noise goes away.

2004 Chevy Impala 120000 miles

Blower motor on 2004 Impala stopped working, actually started smoking through vents. So i removed it and it was seized. I replaced the blower and it didnt work. Fuses are all working. Hooked voltmeter up to the blower wires and read zero volts, so I removed blower control module and checked voltage into it, which also read zero. The fuses for each show 12.7 V and 13.4 V respectively. Is there another part in between the fuses and module that im missing?

Do you have auto climate control or manual a/c?also what model impala do you have?Let me know and i will get you a wire diagram and trouble tree.

It has manual a/c and the model is 3.4 L engine, Base model. Will definitely donate if I get it working.

I emailed you a trouble tree and wire diagram to your personal email.Please post all your question's and finding's on this posted question so other user's can help fix there car.

I found an Open Line between the Battery Positive Voltage Circuit C to the Ground A (I also tried gound on car both where OL) on the 5 Pin blower motor control processor.

I'm assuming that this means when the original blower motor started to go bad drawing to many Amps it burned out the wires and they need to be replaced or do i have to do something else.

[quote:d5e6d61a67="OminousTS"]I found an Open Line between the Battery Positive Voltage Circuit C to the Ground A (I also tried gound on car both where OL) on the 5 Pin blower motor control processor.

I'm assuming that this means when the original blower motor started to go bad drawing to many Amps it burned out the wires and they need to be replaced or do i have to do something else.[/quote:d5e6d61a67]
Terminal c at the blower motor control processor should have power going to it.Terminal a at the blower motor control processor should have a connection to ground.You Need to check those two seperate put the black lead to chassis ground then put the meter on dc volt's and test the Terminal c at the blower motor control processor should have power going to it.Now with the black lead still grounded put the meter on low scale ohm's take the red lead and see if you have less then two ohm's at Terminal a at the blower motor control processor.Let me know what you find for each reading.

Terminal A does have a connection to ground and I can read 1700 Ohms between A and B, but A to C is an open line. I can read a small voltage of 0.1 V between A and B.

A to Chassis ground has 1.6 Ohms between them. C to chassis ground is Open Line.

Sorry it took me so long to get back I've been on vacation and its been too hot to do any work.

I've tried following the wires to under the hood but couldnt find where they come out.

If you have 1.6 ohm's to ground on terminal a to the blower motor processor then that's good.For terminal c to the blower motor processor we are looking for power not ground.So ground the black lead of the meter and put the meter on dc volt's setting 12 volt's or above scale and take the red lead and test for power to terminal c if you don't have battery voltage there then see if you have power to the hvac blower fuse in the under hood junction block.

I checked the blower motor fuse under the hood, (I had checked the fuses on the side of the car but not the ones under the hood) it was blown out of course.

So I went down and got a new 30 amp BUSS plugged it in and now the blower is running, but it is always running on high and never turning off even when the car is off. From the other posts I've read on here it seems like the blower control moduloe has gone bad too and needs to be replaced. Is that true?

At least the motor runs too bad it won't shut off.I emailed you the trouble tree for blower motor always on.Try to work around the part where it asks you to use a scan tool.Let me know what you find.

I worked through the trouble tree and ended up replacing the blower control module. I installed it and everything works fine. Thanks for all the help!!

Glad to hear you got it all figured out.Thank you very much for your donation.Also thank you for using 2carpros.

I have a 2005 Chevy Impala. The blower motor was making noise & then stopped working altogether. I checked the fuses and they were fine. As the motor was making a noise before it quit on me, I replaced the motor and it still doesn't run. What else can I check and how can I check it?

Thanks

[quote:0eb7362ea6="wmgrec"]I have a 2005 Chevy Impala. The blower motor was making noise & then stopped working altogether. I checked the fuses and they were fine. As the motor was making a noise before it quit on me, I replaced the motor and it still doesn't run. What else can I check and how can I check it?

Thanks[/quote:0eb7362ea6]

My suggestion is to check the blower motor resistor for power before you get to the control switch.

Ok so the blower will not come on at all. I thought maybe it wasnt getting power so i took and ran a line straight from the battery to the blower control module, it still didnt come on. The lights behind the switch work, and the rear defroster works but not the main blower. I dont want to spend a fortune replacing the blower control module to find out its not that. What could the problem be?

Why don't you power the blower motor direct from the battery and see what happens

Good idea, i didnt even think about bypassing the module.

OK, so i hooked power to the purple wire going directly to the blower motor, only two wires, purple and black. did not come on. Also, when i checked voltage to the plug that goes to the blower control module, there was no voltage to it either regardless of what position the switch was on.

Is this a manual or automatic AC control system?

Have you tried to check for trouble codes?

Its an automatic control system, I havent checked for codes yet. It isnt my care so i only have limited access to it. I am trying to fix it for my in-laws, it is their only mode of transport and we live in idaho and its getting cold.

I would recommend getting a scan done to check for trouble codes as it would help greatly if there are any codes stored.

Blower motor is connected to Blower control processor which is controlled by the control module and it could be either that is at fault.

The blower constantly runs even when the car is off and the keys are removed. I have to pull the blower fuse to get it to stop. The blower speed control knob also does not control the speed of the blower even when the car is on.(besides turn off the lights on the air conditioning button if the control is set to off.)

How do I resolve this?
Thanks in advance.

does it only work on one speed. check your blower resistor and see if it is burned. it is located under the dash on the passenger side by the blower motor.

[quote:7dedb33f64="rhall77"]does it only work on one speed. check your blower resistor and see if it is burned. it is located under the dash on the passenger side by the blower motor.[/quote:7dedb33f64]

Well, technically, yes it is one speed, but that speed is always on, regardless of where the fan control knob is set and even when the car is turned off with the key removed.

check the blower resistor and see if it is shorted. most likely it is your problem

I pulled what I thought was the resistor out and it appears to be the control module. (circuit board with heat sink) Is there a resistor separate from the control module? The unit I pulled was directly connected to the blower motor and I was unable to locate anything else.

Heater problem
2004 Chevy Impala 6 cyl Two Wheel Drive Automatic

My 04 Impala is having heater issues. The blower motor is fine, I replaced the blower motor resistor but the blower still goes out when you hit a bump. I thought it may be a ground issue but when I changed the ground the motor runs constantly. What gives

thats it, you got it. does it look burned or anything.

recheck the blower motor
when its out check for power and ground at the motor if have both suspect and replace blower motor

Unfortunately no, nothing appears burned.

i think i would still try a new one in it to see if it works ok. your local dealer should have one

I will try that tomorrow. I will let you know how it goes.
Thanks for the responses!

rhall77,

Thanks so much for your responses and advice. This was exactly the problem. It now works like a champ!

Just for anyone else that encounters this problem:

The Blower Control Module was plastic riveted and no screws were used to attach the BCM to the car. I have yet to find the best way to re-attach the BCM, but don't really care too much about that as long as my blower is working again.

A/c blower motor work until you hit a bump in the road the a/c fan shuts off but it will restore itself ,when the fan blows the air volume varies even at high speeds whats causing this problem , and what kind of a repair bill am i looking at ? ,is this an easy fix ?

check your connect at the blower resistor. it maybe burned. sometimes you can just get away with the resistor, it is located on the passenger side under the dash by the blower motor. turn your key on and wiggle the wires and see if it cuts in and out

It's been about a year since the last reply to this thread but hopefully some of the original respondents are still on here. I have a 2004 Impala SS Indy and I've been having an issue that other posters in this thread have mentioned- blower will stop working and then work again upon hitting a bump or smacking the dash, etc. As the months have gone on I've had to get more involved in the fix...e.g. smack the underside of the blower assembly with rubber mallet, remove the dash control module and jiggle the cables, etc. to get the blower working again. I am now at the point where absolutely nothing I try works and of course it's the coldest day of the year. I have never had the issue with this particular car of the blower working on only one speed, as I have had that issue with other Impalas, so it did not scream issue with the resistor to me. I've also not had the issue of the blower not turning off when the car is off. In trying to diagnose this issue I've exhausted my brain and everything that I've been able to diagnose defies everything I understand about electrical circuits. I'm hopeful somebody can makes more sense of this than me. Here's where we're at:
-Fan doesn't spin at all.
-All actuators and compressor works
-All fuses under hood and both side fuse boxes test good.
-Replaced blower resistor and blower motor without change in result
-At the 5 pin connector (I'll call it connector 1) going to the blower resistor I have battery voltage at pin C at all times.
-Connector 1 ground pin A has less than 2 ohms resistance with chassis ground.
-Connector 1 pins D and E have no continuity with each other or pins A B or C when not plugged into resistor (no short within the harness)
-Connector 1 pin B has less than 2 ohms resistance with it's wire in the connector to the dash control module.
-With car running, connector 1 pin C registers a voltage varying between 0 (off) and .15 volts (highest speed) depending on the speed setting
-I hotwired connector 1 in the following way- grounds on pins A and D jumped and hots on pins C and E jumpered and removed the resistor. On the 2 pin connector doing going to the blower motor (I'll call it connector 2) I have full battery voltage between the two pins (as would be expecting expected from bypassing the resistor.)
-Plugging connector 2 into the old blower or new blower does not spin the blower at all even though this set up should be bypassing both the resistor and dash control and providing direct 12v battery access.

I am completely stumped. It seems like I have voltage but no current. Have no idea what to do next. TIA

It sounds like the blower controller is bad is this what you replaced? Here is a guide to help check for power and the blower motor wiring diagrams so you can see how the system works and the location of the controller:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

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

Hi Ken thanks for the reply. Yes the bcm/resistor pack was replaced. Connector 1 that I referred to is the connector that plugs in to that control module. I have even gone so far as to disconnect it from the resistor and hotwire it so that the grounds and the hots are connected to bring power directly to connector that plugs into the motor but despite having battery voltage at that final connector it does not spin either the old motor or a brand new one.

Ended up taking it to the dealer who took apart more of the car and got to a 10 wire connector behind the shifter that had melted the red wire to the resistor. Think I'm going to change the 30 amp fuse under hood to something smaller.