A/C Question
Thread Starter
Instructor
Joined: Nov 2002
Posts: 158
Likes: 0
From: Motown mi
A/C Question
My A/C runs fine as I am crusiing at highway speeds. As soon as I get into the city, and the engine temp rises it runs crappy(considerably warmer). Any ideas, I currently have R-134, but will swap back to R-12 if I need to( 12 is still legal in Canda and it is 40 minutes away) seem to have a full charge and no leaks. Thanks, BTW it is a 88 Auto.
Burning Brakes
Joined: Aug 2002
Posts: 926
Likes: 2
From: chandler az
Re: A/C Question (boxerlover79)
You probably don't have enough air flow through the condensor. Do you have the booster fan? If you do try wiring it 'on' and see if the problem goes away. You could also have a low charge of 134.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: A/C Question (boxerlover79)
Regardless of gas, you need a manifold gauge set to check it out. There is a fan switch on the high pressure line. When the high side gets to 233psi, the switch opens signalling the ECM to ground the fan relay turning the fan on. The cool air flowing across the condensor lowers the pressure and the switch closes at about 170 - 190 psi and the ECM removes the ground from the relay turning the fan off. The high side needs to stay within this operating range for good vent temps because it will keep the low side or boiling point of the gas in the area of 22 to 28 psi (which is approximately 30 to 38 degrees) - especially at idle. A guick test of the switch is to disconnect it. Fan should run, and if it does, you can see if the vent temps drop. You really need to see what the pressures are to check everything out. Off hand, the charge may be too low for the switch to operate properly, but depending on how the conversion was done, the condition of the compressor, a lot of other stuff could be going on too.
Thread Starter
Instructor
Joined: Nov 2002
Posts: 158
Likes: 0
From: Motown mi
Re: A/C Question (jimswhite92)
If everything gets back to good running condition, do you think I should swap backl to R-12 just to get that extra couple degree drop in vent temps? I am in Michigan now, but moving to Texas in a few weeks. Thanks
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Racer
Joined: Oct 2002
Posts: 293
Likes: 0
From: Newnan Ga
Re: A/C Question (boxerlover79)
If you get your r134 right you won't need r12 or want it. Your problems most likely are related to something else or a combination. Check to make sure you don't have a bunch of debri between the condensor and radiator. These cars are bottom suckers and will vacuume up trash off the road. You could need a new filter drier or one of those new fancy throttling orafice tubes. I'm planning on trying one of those soon to see how much more ac performance you get with it.
