ac troubles [Archive] - GrandAmGT.com Forum

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Michel
05-30-2012, 08:47 PM
I have an 02 gt with 3.4 engine and compressor started making loud noise and didn't seem blow very much at all on speed 1 and 2 i put can of r134 with leak sealer and oil in it and a small can of reg 134 blew cold for day and now back to blow warm air and the comp and clutch seem be moving freely....no rust on them like i was told look for..........any ideas try help me fig out prob and how to fix it thanks.............

AaronGTR
05-31-2012, 07:21 PM
Probably has a leak, or a bad compressor, and/or the metering orifice in the lines could be plugged with metal flakes from the compressor wearing. Probably need to have the compressor checked out and have the system checked for leaks with a UV light or a vacuum test (if it's empty of refrigerant).

Michel
06-01-2012, 07:39 AM
Thanks for the help...I assume the vacuum test needs be done by a shop or can I DIY if so how do I do that...

AaronGTR
06-01-2012, 03:43 PM
To do it right takes some special equipment to make a high vacuum and fittings to attach to the lines, and the system needs to be evacuated first if it's not already empty. Probably better to just have a shop do it.

pauljs75
06-02-2012, 01:12 PM
Not blowing right at fan settings 1 & 2 is a blower motor resistor, not your A/C unit. The resistor is up under the front passenger seat. It's good if you can get the passenger seat out. If you can't get the seat out, you'll need a circus midget to get the resistor out - otherwise you risk messing your back up good. Might have to get the upper kick panel (more like knee panel), and there may be an ECM unit which slides and unhooks out of the way. (Been a while, not sure if those were necessary to remove for access.) Unbolt the blower motor and the resistor is right there with it. They tend to get crap and stuff on them and overheat, and the insulation flakes off. And that's how they fail.

Keeping a vacuum cleaner handy is also a good idea when doing this job. There's usually crap that accumulates in the trough the blower motor sits in.

Also be aware that too much refridgerant in an A/C unit can mess it up as bad as not having any. It has to be within spec. to work right.

If doing anything, I'd clean up the outside of the A/C evap unit if I could get at it and make sure the vent selector and air blending door operates correctly before messing with actual refridgerant. (Sometimes the A/C gets perfectly icy cold, but if it gets covered in crap or doesn't drain condensation and ices up, or the blender door doesn't work the full range - no chill where you want it)

I also think there are some sensors on the Grand Am... You should get a SES and an appropriate trouble code if there's actually anything wrong with the refridgerant pressure or compressor itself. Don't see those, do the other stuff first.