AC problem? - CamaroZ28.Com Message Board

Go Back   CamaroZ28.Com Message Board > 1967-2002 F-Body Technical Discussion > General 1967-2002 F-Body Tech

Reply Post New Thread
LinkBack Thread Tools Search this Thread
Old 05-28-2013, 07:39 PM   #1
Registered User
Join Date: Nov 1998
Location: Louisville, KY
Posts: 2,689
AC problem?

It's finally starting to warm up around here. I turned the AC on today, and nothing but warm air came out. I tried it about three weeks ago, and it worked. I don't think the compressor is coming on, as I don't hear the "click" I usually hear when it comes on. There are no strange noises from the compressor. I seem to remember the relay can be removed, and a jumper used to check to see if the compressor will come on. Which pins do I jumper, and I'll listen to any other suggestions about checking the AC.
Artificial intelligence is no match for natural born stupidity.
moparman is offline   Reply With Quote
Old 05-29-2013, 12:21 AM   #2
Registered User
ACE1252's Avatar
Join Date: Mar 1999
Location: Kernersville, NC
Posts: 1,920
Re: AC problem?

If your AC system has lost it's charge, then the pressure sensor in the system will prevent the compressor from coming on. It's to protect the compressor, so don't try to bypass it if your system pressures are not correct.

There could be other reasons like a bad relay or a few other things. I know it can hurt the wallet, but I'd leave the AC troubleshooting to the certified techs. I recently had to have my low pressure schrader valve replaced because it was leaking. I had the good folks at Flow Chevy do the work. Approx $200 to discharge the system, replace the valve, and recharge the system.

The only thing that kept most of the charge in the system is that plastic cap on the port. There is a seal in there that is a last resort to keeping the system charged in case the valve leaks.
Eric R.- Electrical Engineer - ODU
1996 Blue Z28, 6M
CC503, 1.6 Pro Mags, Kooks, Stock heads, K&N CAI.
ACE1252 is offline   Reply With Quote
Old 05-29-2013, 12:56 PM   #3
Registered User
Join Date: Nov 2007
Posts: 905
Re: AC problem?

As ace says, running compressor w/o refrigerant can destroy it. PCM will not pick relay if the sensor is reading below 22 lbs. Here is the schematic ref . You can pull relay and with ignition on and engine off jump B1 to B4 you should hear the clutch click. If engine is running only do it momentarily enough to see if clutch plate engages and compressor moves w/o squealing. Since you say you can't hear clutch click, most likely you lost the 22 lb cut off threshold, no need to run the engine. If clutch activates w/jumper , next step would be to get a 134 can w/a cheap gauge attached and verify pressure w/engine off. If below 22 lbs start adding.. At current warmer temps above 70* F one 12oz can of 134 on and empty non running engine system should give the system at least 22 lbs enough for the compressor to start sucking when engine is turned on. ALSO when you jump the clutch it will most likely throw an AC DTC (w/o SES indicator). That prevents the PCM from picking the clutch until the PCM is reset. It can confuse the heck out of you after you add 134 and it still does not run...Good practice is to reset PCM BEFORE trouble shooting to eliminate any old AC codes preventing clutch pick and AFTER trouble shooting to clear any DTC's you created. Also some try jumping the pressure sensor --DON'T -- the pressure sensor is a 0-5v sensor feeding the PCM not a switch, jumping it will throw an AC DTC in the PCM and prevent subsequent AC activation, again causing confusion after a fix and requiring a PCM reset.
I'm Bob.. 1994 Z28, A4, Stall, CAI, Cam, RR's, 342 rear, LT's , CatBack, Tuned

Last edited by bobdec; 05-29-2013 at 01:16 PM.
bobdec is offline   Reply With Quote
Reply Post New Thread

Similar Threads
Thread Thread Starter Forum Replies Last Post
Throw out bearing problems! Matt W LT1 Based Engine Tech 6 04-24-2015 01:54 AM
Starting Problems.... Help! AlaskaZ28 LT1 Based Engine Tech 12 04-17-2015 09:54 AM
stall no start greenzee28 Fuel and Ignition 7 03-26-2015 10:13 AM
New girl with new car and new problems Magenta_Hearts New Member Introduction 4 03-25-2015 11:24 AM
94 LT1 Starting Problem (Urgent) liamcg97 LT1 Based Engine Tech 16 12-27-2014 09:27 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 09:06 PM.


Copyright © 1996-2013 CamaroZ28.Com. All rights reserved.