Kurt 86 GT

Hi,

I'm starting a new thread b/c I've narrowed down the reason the engine fan on my 1986 GT always runs when the A/C is on even if the engine is cool. It appears the A/C High-Pressure switch is turning the fan on. I have also checked the other engine fan components like the fan temp sensor and swapped out the fan relay with a new one. All these are working properly. So I’ve definitely isolated the issue to the A/C High Pressure switch.

I'll be able to get to my car again this weekend but wanted to order any necessary parts before-hand.

My questions are the following. Btw, the A/C does cool fairly well as is. I’m mostly annoyed by the constant running of the engine fan and don’t want to burn it out.

1) Is there a High Pressure switch on the Receiver/Dryer than can be swapped out without having to remove the Receiver/Dryer and de-pressurizing the system? Or is the High pressure switch integral to the Receive/Dryer?
2) When I get gauges on the High Pressure side and if the readings are high, what does that mean? The A/C is actually cooling. Does that mean I should “just” swap out the Receiver/Dryer?
3) What pressure reading should I have on the High Pressure side?

Thanks for everyone’s help in keeping her going.

flagreen

... the high pressure switch is located on top of the reciever / drier. Removing it will discharge the system. Bentley does not give the normal operating pressure. The only psi figure given is that of the safety seal which blows at 500 - 570 psi.

If I were you I would take my buggy to have the system checked at a certified shop. If the pressure switch is ok and the pressure really is too high I'd get the system flushed as there may very well be some debri clogging a line. Then have it evacuated and recharged as usual.

It's an expensive PITA but then that cool air is nice to have. Because of the high pressure the system runs at normally it's not anything to take chances with.

Liam :-)

allangering

I am really not an expert in AC systems.I see there is a AC Pressure Transducer that is supposed to monitor the pressure in the system and it controls the fans and the compressor. I am not certain whether a failed transducer would result in the system over pressurizing as you describe but it is worth consideration. I think that you really need a set of A/C gages to see precisely what your LOW and HIGH side pressures are.