500E a/c problem
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Junior Member
Joined: Aug 2009
Posts: 18
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92 500E
500E a/c problem
My 92 500E's a/c works fine at first start but after about 30min to an hour the air isn't cold anymore. Then the next day it's the same thing - works fine when you start and after a while no cold air again. Freon level is fine. Mine is the dual-zone climate control with 2 thermostat wheel knobs. I also notice that after it malfunctions, the red lights on the 2 center buttons (EC & air recirculation) stop working. I was wondering if any of you have experienced this kind of problem.
MBWorld Fanatic!
Joined: Apr 2007
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E
If you Absolutely sure your freon levels are OK....R134a is a little picky when it comes to pressures...
Two possible issues:
1) Your vacuum pods have developing leaks allowing outside air to sneak in.
2) Your push-button control unit has solder cracks in the board
I would definitely check the pods first. Remove the glovebox and you will find the main vacuum pod unit with (7 IIRC) vacuum cables going into it. Use a mityvac and check for vacuum on all of them. My bet is a few of them are toast. It does require removal of the dash which is a few hour job, but it's not as bad as everyone makes out. IMO.
Two possible issues:
1) Your vacuum pods have developing leaks allowing outside air to sneak in.
2) Your push-button control unit has solder cracks in the board
I would definitely check the pods first. Remove the glovebox and you will find the main vacuum pod unit with (7 IIRC) vacuum cables going into it. Use a mityvac and check for vacuum on all of them. My bet is a few of them are toast. It does require removal of the dash which is a few hour job, but it's not as bad as everyone makes out. IMO.
