91 LS 400 A/C works intermittently

treyofhearts63

I have a 91 LS 400 that I purchased a few months ago. The car was maintained well, and in fact the AC was charged last summer. The problem I have is that I turn it on, the AC light is on and I get cold air for a few moments, then it flashes off and stops pumping cold air. I live in Atlanta and it gets hot here so i need my AC. Also, at times, it will work fine for a while pumping cold air, then stop. I believe it has something to do with the controller as the AC light is on when it is working and off when it isn't. Any ideas are appreciated. Please feel free to email me at treyofhearts@yahoo.com

Mr_Shiftright

Yes, it does sound like the control module that sets the a/c temperature. It may be sensing the wrong temperature, thinking that your dialed in temperature has already been reached. Of course, I'd have it professionally diagnosed since I suspect this is not a cheap part.

q45man

But in reality it's more like 15%-25% of R12 leaks out of 10 year old cars annually. This is enough to cause a major problem and shut down the compressor [pressure shut down switch].
We service many older Lexus and typically they need an evaporator/compressor about every 8-9-10 years as mileage exceeds 120,000.
Watch out for leaking power steering pump/lines as the fluid falls on the alternator causing failure, plastic radiator and overflow bottle leaks, illumated gauge needles, front and rear suspension bushings - tension rods and EGR vacuum control valve are other common high mileage failures.
T3 Automotive Atlanta