Air Conditioner

[magalicano]

Hey guys, I have been having some problems with my 1992 LS-400's A/C. A few days ago, the check engine light came on. Within a day the A/C went out on my wife (boy was she hot, literally and physically).

My local mechanic hooked it up to a vacuum line, but could not find the leak. He put dye in system to help him find the leak the next time it happened. I picked the car up on Saturday and realized it was not blowing as cold of air as it had in the past. I drove for while and it began to blow warm air. Per the mechanic, he still could not find a leak, but said it could be a problem with A/C Control Unit or the fact the A/C rubber hose is deteriorating on the inside and is causing a blockage in the system.

I'm hoping maybe someone has some ideas or can let me know if the older models had problems with hose deterioration.

Thanks

P.S. Still the best informative site on the www

[obergc]

If your 92 a/c plumbing s anything like my 93, (although your's is probably an R12 system unless it has been converted to R134), there actually isn't a whole lot of rubber type plumbing in it, the majority of it is metal tubing. My 93 has 100K and I recently had to change the compressor since it was frozen up, I had a blinking a/c light on the a/c control panel. I cut into the suction line next to the manifold on the compressor to install an inline filter that I bought at Pace Compressors in Tampa, Fl for $25. This section of the suction line has about 15" of rubber tubing. The inside of the tubing is vinyl lined and it looked brand new inside. Don't know if your tubing is made of the same material since my car came with R134a from the factory. If a line was deteriorating, an inline filter would catch the crap and keep it out of the tiny orifices in the a/c system. A few questions for you, did your mechanic put R12 in your a/c or was it converted previously? Do you have a blinking A/C lite on the control panel? Are you certain that the compressor is running with the a/c turned on? If you have a blockage in the expansion valve that is located in the evaporator core, it will try to pull a vacuum on the suction line when the compressor is running. Best thing to do is get a set of gauges and connect them to the suction and high pressure ports and see what the system pressures are when the compressor is running. You should see some sweating on the suction line and it should be cool to the touch of everything is working the way it should.

Curt