Mitsubishi Repair: air conditioning, r 134a, diamonte

Question
1992 Diamonte LS (I love this car have had it since new).  a/c is acting erratic; sometimes in auto will work for a while then quit; if I turn to high fan will work, or sometimes, not.  Most recently it was working fine then quit for 30 seconds; worked for 10 seconds; quit for 30, etc.  It is usually when the day has heated up that it quits, of course!  Dealership has had it 3x's - no answers.  Probably because when it's there it works fine! Thanks.

Answer
Deniece,
It's possible there is a sticky clutch on the compressor, or perhaps a relay is sticking.  When eletrical components (like relays) get hot, they tend to loose connectivity.  So a possible scenario could be that your A/C is working just fine, then when it reaches a certain temperature, it shuts off.  After it cools down, it activiates again.  It's not a common problem, but it could happen.

I would recommend bringing your car to another repair shop, other than the dealership.  If they cannot figure out the problem after 3 times, it's time to get another opinion.  There are usually plenty of shops that specialize in A/C repair.  Plus, dealerships typically do not want to handle older A/C systems since they use the older R-12 refrigerant.  Most cars made after 1994 used the R-134a refrigerant as required by federal law.  You may want to have your A/C converted to the new refrigerant, and the A/C shop that does that may figure out what your problem is.
Good luck!