2001 Jimmy A/C issue

My A/C does an odd thing. When it blows, it blows ice cold. It will, unfornately for me, cut out, blowing hot air. I do not believe that its heat that it's blowing, but outside air. It will blow warm/hot for a while, then the cold air will start up again.

I am not very versed in A/C repair. If its a relay or something I am good to go. But if its the compressor, I am screwed.

Any ideas?

Guess what- my '95 Jimmy does the same exact thing. I haven't figured out the cause, but I'm assuming it's not something cheap. I'll keep an eye on this post and maybe we can both come up with a solution.

1 week, 25 views and no one has ANY ideas?

Grrrr...

Hello, Gents!!

Just had a friend ask me to look into the same problem on his 96. We spent about an hour, and while I have a few ideas for you, we did not positively correct the problem.

The issue is that the AC clutch is not staying closed. Normally, this is due to 2 conditions: 1) The AC relay is shot (There are a bank of three relays on the firewall on the 96 model, the AC relay was #2), or 2) Your overload switch is malfunctioning.

If the AC comp gets too hot, there is an overload switch that shuts the AC compressor off , in an attempt to keep you from buying a new one. If you are noticing quite a bit of cutting in and out, but the AC does work at times, chances are, its your overload protector switch. This is a normally closed thermal device (Should show continuity when cold). If the compressor gets too hot, it opens, and the AC won't come on again until it cools down and the overload device again closes.

If you are in a hot climate, this may be normal for compressor. Sounds like the design is bad, and it just overheats too much. You could ask the dealer if the overload sensors are know to go bad on your compressor.

Now, our issue was much worse. The clutch on the compressor was definitely not closing. I hit it with the battery, and it closed just fine. So, I too would think the overload or relay in this case. I checked the relay, and it was fine. I even switched it with one of the other working relays and still no go. I checked the overload switch, and it was fine. I even jumpered a bypass, and still no go. Then it got weird. I had correct continuty to all grounds, and between the compressor clutch hot pin and the relay hot pin. When I checked the relay in/out voltages, everything was still correct. If all of these checks are good, that clutch should close, and it did not. Gremlins. Gonna have to spend more time on this later.

I hope something here helps you fix your problem.

J

hey check for the power connection at the compressor
see if you can wiggle it and make it go on and off
found mine had a bad connection and replaced the connector
from chavy cost bout 25.00

Thanks, I will give that a try!!

JM




hey check for the power connection at the compressor
see if you can wiggle it and make it go on and off
found mine had a bad connection and replaced the connector
from chavy cost bout 25.00

Recently bought a 2001 Jimmy SLS that was exhibiting similar problem. Bought from CarMax so during the 30-day no-questions warranty period had it in the shop 3 times. Eventually Svc Mgr put his 20yr GM veteran on it and within 5mins he knew it was the AC Pressure Cycling Switch, about a $20 part and the problem has been fixed now for 3mos.

Recently bought a 2001 Jimmy SLS that was exhibiting similar problem. Bought from CarMax so during the 30-day no-questions warranty period had it in the shop 3 times. Eventually Svc Mgr put his 20yr GM veteran on it and within 5mins he knew it was the AC Pressure Cycling Switch, about a $20 part and the problem has been fixed now for 3mos.


Now that makes sense. Thank you very much, I will have to check that out.

Sincerely,

MM