Air Conditioning/Blower not working

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.

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.

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.

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

Unfortunately no, nothing appears burned.

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?

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

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.