on the road A/C failure
 

So there I was at 30,000 feet, with two MiGs on my tail, somewhere over Washington DC, with the outside temperature around 97 degrees, and my beautifully-functioning A/C suddenly started blowing ambient outside air temp...the system strained to keep up by increasing fan speed / air flow, but no more cold air.

Aborted trip, landed, checked fuses, waited until dark, fired engine up, A/C worked again. This morning enroute to work, no cold air. Recently had new pushbutton unit, new aux water pump and new monovalve repair ket installed. Is it my monovalve again, or did I suddenly lose all my freon?

A million dollar reward for the right answer.....

JoeB

I forgot to add - 420SEL, 1987, 250k.

JoeB

Klima relay desoldered?



Joe

thanks - but I'n not sure what a Klima relay is....

JoeB

Have you checked belt tension, there is a sensor that will cut out compressor if the belt slips. It will reset when you kill the engine and restart.

BTW, it could've been much hotter! You're lucky the MIG's didn't flame your tail!

Good luck,

What type MIGs? Usually, they are more maneuverable then you, but you can out-dive'em. Alternatively, try to out-curse'em, but you'd lose that one.

follow-up: took car to dealer, replaced "klima" relay (climate control relay switch) and added freon with dye to identify source of leak. A/C works fine; will take it back after 1k miles so they can look at the system with an ultraviolet light to spot the leak.

The dealer is MB of Alexandria (Virginia), which is an offspring of American Service Center of Arlington, which also has a good rep. Have now received good service twice at MB of Alexandria.

JoeB