AC on the 80 (1 Viewer)

[Trunk Monkey]

Got a question about the AC on my 97 80. It's been pretty hot here (high 90's, low 100's) and the AC will kick on and off it's cooling cycle. I'm guessing that it's probably designed to do just that so that it doesn't overheat the engine, it just seems that it's doing it more frequently lately. One of the other guys in my club has a 94 that's doing the same thing (as we speak) during his road trip to LA.

The truck was hit recently and the AC dryer on the front frame rail got bent. When the shop bent it back they kinked one of the lines and caused a leak. They fixed the leak and recharged the system, so I know I've got a full charge of refrigerant (unless they didn't fix the leak well enough). I would think that the AC systems on these trucks would be beefy enough to take running in high temps for awhile.

Any thoughts?

 

[BigMac]

I think the receiver/drier should have been replaced. Any structural damage to the r/d is very bad, and a leak that caused the system to lose its charge is grounds for r/d replacement before system evacuation and recharge. Yes, the stock a/c will function perfectly in sustained desert heat. Good luck, BigMac

 

[Beowulf]

>> Yes, the stock a/c will function perfectly in sustained desert heat. <<

Agreed.

Check the obvious things first like the belts. If they are in good shape and the tension is correct then start testing that repaired dryer.

-B-

 

[thorvald]

is it keeping cool?
is yours an anniversary issue? if so, I believe they have cliimate control which kicks on and off on its own, someone said you can override it using manual control. someone with a better memory or 97 might be able to help if its not your receiver/dryer causing it.

 

[Scamper]

Yes, I've got one of those automatic systems on my CE and it does kick in and out automatically every few minutes. But the key is that it does keep you cool--it's just regulating the cabin temperature to whatever you've set it at. Nothwithstanding everthing the others here have said, if you aren't getting cool air out of it, then you have a problem, otherwise it sounds okay.
Tom

 

[Seminole]

8)
If your compressor is cycling on and off frequently, like at stops and idle, then your system is low on freon. There is a low pressure cut off switch that will cut off the compressor in order to prevent damage to the system. The frequent cycling is a warning to have your system recharged.
HTH

 

[Trunk Monkey]

Thanks for the responses. The AC dryer wasn't damaged at all, just the bracket that holds it to the frame was bent. When they bent it back, they said they kinked a line and caused a leak. Guess it's going back into the shop for a check up. Thanks again.

Cory

 

[Trunk Monkey]

Just a little follow up with the AC problem on my 80. Took the truck back in today and they evacuated the system and refilled it. One comment the tech made was that I shouldn't expect the AC to be really cold at idle. He said that "since these trucks don't have secondary fans on the AC compressors, they run a little warmer at idle and cooler with air blowing over the compressor at speed." He also said that the heat from the supercharger probably isn't helping either. But with the refill it is noticeably cooler, he said there may have been an air pocket in the system that was kicking the compressor on and off.

Thanks again for the comments.

 

[Eduardo96FZJ80]

FZJFillmore,
IIRCC there was a recent post on this subject.
I too have noticed that in traffic and with no airflow thru the condensor, the cooling is a lot less.
C-dan made mention of an electric fan that was for the dual AC units. A little pricey if I recall!

 

[BigMac]

Is there an electrical engineer in the crowd who could design a circuit which, when armed by a driver-operated switch, would automatically kick on a front-mounted auxiliary elec pusher fan when the vehicle speed fell below, say, 15mph? There must be some minimum voltage level in the speed sensing circuit that equates to low vehicle speed - how could it be detected and used as a trigger? BigMac

 

[cruiserdan]

The non-US fan is an 88590-60010. It lists for $288.37
It fits perfectly on the RH side of the condensor on existing tabs. I have mine on a manual switch and turn it on when I feel like it.

 

[Rogue]

Dan,

Does it make a big difference?

 

[cruiserdan]

Rogue,

I think it makes a noticable difference. When I'm running the A/C I kick the fan on and leave it on.