Hi, I am new to this site, but I have a 04' MC and the A/C has been "slowing" when the breaks are applied and recently has been cutting off at odd times such as a bump in the road and just will not come on at all. Any help is appreciated thanks.

 

Welcome to the forum...

Since the AC slows down when the brakes are applied... It sounds like a bad ground somewhere.... Possibly a bad battery as well.. I would start by checking all the connections at the battery... for rust and corrosion... I would clean them thoroughly.. and or replace them if necessary... I would also take it to your local auto parts and have the battery checked.. Its free.. How old is the battery?

 

STUMPMI,

Thanks for the welcoming and the reply. The battery is about 2 weeks old. I find no rust or any voltage drop on the battery. It has recently stopped working on a bump in the road. I was thinking a loose connection, I am stumped...

 

**#2 post of same issue on my 04' Monte Carlo, at first the fan would stopped anytime I hit a bump in the road and a slight bump of the dash next to the fan control switch would bring her back on.

Now the fan has stopped blowing completely, but the compressor kicks on and off as it is suppose to do...It is hot here in Georgia in late August so...

ANY AND ALL help is needed and appreciated thank you! I have the dash taken apart to access any and all views..

BG

 

I am considering installing a 3,500 WATT DC Converter and mounting a 120 volt a/c window unit in this car. I give up...heck it is not even mine, it is my girlfriends and she drives my truck...lol.

 

I've been having a simular issue on an 03.
But when my blower becomes inop, the overhead info center is also not functioning and the green cruise light becomes solid or flashes in the cluster.
I plan to investigate thoroughly this weekend

 

@BGW - No need to start duplicate threads for the same issue (a simple bump asking for more info is fine, other wise you begin spreading the diagnostic help). I've merged the two.

If the blower stopped completely, I am suspecting a failed blower motor. Remove the lower passenger side kick panel, you will then have access to the blower motor. It's one connector and I think 4 screws holding it in (I believe 7mm hex head screws). Pull the motor out.

Test 1 - Spin it by hand. Is it tough to move? Does it wobble or do anything that seems odd in it's travel (like a rough spot).
Text 2 - Connect the fan direct to the car battery (I believe it only has a positive and negative connection and I'm not sure the polarity matters, I think either lead can be positive or negative). If the motor is good, applying a straight 12v to it direct from the battery will cause it to run at full speed. If the motor does anything that is NOT full speed (or nothing at all), you simply need a new blower motor.

If the motor checks out, my next suspect would be the blower motor resistor (cheap part, but a bit challenging to get to, it's in front of the blower motor, tight to the firewall and I believe 2 screws on it, but being an 04, GM may have "heat staked" it (so you have to bust/cut, drill the heat stakes and replace with screws).

Hope this helps.

 

If the bower motor stopped working it can be a few things. Check both the 20A and 25A AC BLO fuses. If hitting the side of the dash made it work for a bit it could be a bad HVAC control module or loose connection there. It could also be a bad resistor pack and finally bad motor.

If it were me I'd check the fuses first. Then use a DMM along with this wiring diagram to diagnose the circuit to see where the fault lies. You should be getting battery voltage at the wires corresponding to the different fan speeds going into the resistor pack. Those lines run through resistors in the resistor pack to give the motor different levels of voltage to vary the fan speed. You'll want to also check G202 as that ground location is needed for the motor and relay in the resistor pack to function.
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