Symptoms for a new AC clutch?

[kemo sabe]

I noticed on my 91 1500 the ac light on the dash flashing and it wasn't blowing cold and then looked and the clutch was not engaging. I've checked to see if the refrigerant was full and it was. So would I just need to replace the AC clutch? I haven't dealt w/ any HVAC ever, but my truck has the 134a setup. Any help would be appreciated.

 

[shorepatrol]

The compressor must be on to check your charge.

 

[Ruger_556]

How did you check the charge? A/C is best left to those who know what they are doing... That said the clutch must have 12v to engage. If it has that and it's not engaged you know where the problem is.

 

[someotherguy]

The A/C light flashing on 88-94 is letting you know the control head detected too-frequent compressor cycling, indicating a low charge. Due to this it has disabled your A/C. You can clear the error in the control head by momentarily disconnecting your battery and then see if the A/C works after you reconnect. If the charge is just a little low, it will run a short while and after it cycles too many times it will set the error again and disable A/C, with the flashing A/C letters you're familiar with already.

There's also a TSB out where this feature of the control head can erroneously set the code, and fixing it requires removing the wire from the control head that allows it to set the error. Someone just recently did a write-up here with the info in it. -> http://www.gmt400.com/forum/showthread.php?25539-88-94-A-C-Repair-(How-to)

Richard

 

[kemo sabe]

How did you check the charge? A/C is best left to those who know what they are doing... That said the clutch must have 12v to engage. If it has that and it's not engaged you know where the problem is.

I used those recharge cans w/ the gauge on them to refill.

 

[kemo sabe]

The A/C light flashing on 88-94 is letting you know the control head detected too-frequent compressor cycling, indicating a low charge. Due to this it has disabled your A/C. You can clear the error in the control head by momentarily disconnecting your battery and then see if the A/C works after you reconnect. If the charge is just a little low, it will run a short while and after it cycles too many times it will set the error again and disable A/C, with the flashing A/C letters you're familiar with already.

There's also a TSB out where this feature of the control head can erroneously set the code, and fixing it requires removing the wire from the control head that allows it to set the error. Someone just recently did a write-up here with the info in it. -> http://www.gmt400.com/forum/showthread.php?25539-88-94-A-C-Repair-(How-to)

Richard

Ok so it started running cold after I unplugged the battery. I'll drive it around this week and see if the A/C light starts flashing again.

Do you guys think those recharge cans are worth it or should I take it somewhere to get it recharged?

 

[someotherguy]

OK, so it's been converted to R134a, since originally your '91 would be R12.

Lots of people have gotten by using the DIY cans but I've lived through enough A/C problems that I really believe you should have a qualified person use a real set of gauges to properly charge the system and evaluate its condition. You might make it "work" with a DIY can but a real A/C tech can tell a lot about what's going on in the system by observing it in operation on real gauges.

If it acts up again soon definitely get the charge level checked; if that's OK then your next step is to follow that post I linked and disable that feature by removing the wire.

Richard

 

[kemo sabe]

OK, so it's been converted to R134a, since originally your '91 would be R12.

Lots of people have gotten by using the DIY cans but I've lived through enough A/C problems that I really believe you should have a qualified person use a real set of gauges to properly charge the system and evaluate its condition. You might make it "work" with a DIY can but a real A/C tech can tell a lot about what's going on in the system by observing it in operation on real gauges.

If it acts up again soon definitely get the charge level checked; if that's OK then your next step is to follow that post I linked and disable that feature by removing the wire.

Richard

Thanks I appreciate the help.

 

[Lordkay972]

I noticed on my 91 1500 the ac light on the dash flashing and it wasn't blowing cold and then looked and the clutch was not engaging. I've checked to see if the refrigerant was full and it was. So would I just need to replace the AC clutch? I haven't dealt w/ any HVAC ever, but my truck has the 134a setup. Any help would be appreciated.

Lucky for you, I'm an expert on this subject. From recent experience, there's only one way to fix this. I wrote a tutorial on it. Check it out.
http://www.gmt400.com/forum/showthread.php?t=25539
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