Climate control problem - 400e - PeachParts Mercedes-Benz Forum

rdsc49 · #1 07-02-2003, 09:53 PM

I have a 92 400e. The climate control blows hot air!
I had it in to my MB specialist, and he said the gas was up, but the compressor was not getting any power. I didn't have time to let him tinker, especially at his shop rates. The fuse is ok, but I haven't got much further than that. This thing has more sensors and control modules than the space shuttle. I wondered if anyone has any ideas on things I can look at before taking it in for the inevitable $1000 diagnostic + parts??

mike690003 · #2 07-02-2003, 09:57 PM

It might just be your climate control unit. See if someone will let you borrow one, and then try that unit. Or jam the buttons really hard on your climate control unit. Those units go wacko over the years and are the main culprits for a "brokec" AC. I have to jam my buttons really hard in order to operate my AC.

rdsc49 · #3 07-03-2003, 07:26 PM

thanks Mike I tried your suggestion but it didn't help.
I have noticed a few postings re air coinditioning that mention serpentine belt slippage as a potential to cause the compressor to not engage. My belt squeals, and I was planning to replace it. How much slippage would cause the compressor to not work at all, or only for short periods? I think it may engage briefly when the engine is cool. ... Bob

400E · #4 07-04-2003, 08:16 AM

It doesn't take much slippage to shut down the compressor. Once I went through a puddle of water, causing the belt to slip for a split second, which was enough to shut down my compressor. As I recall, I had to shut down and restart the climate control system to get it to work.

amg280 · #5 07-04-2003, 06:20 PM

Funny I should read this today. My belt of my 400E started squeeling lately. And ever since i owned the car, when i get on the gas and after it shifts, the ac shuts off due to slippage. Today, I tightened the belt and it took care of all my problems. The ac stays on all the time, and the belt doesnt squeel anymore. My belt was so loose i could take it off and put it back on with my hands without loosening anything. Also, these motors are notorious for power steering leaks. Check to see if the belt is doused in p/s fluid. If not, its most likely a bad push button control unit like Mike said. Try jumpering the two a/c wires on the reciver drier and see if the ac comp. kicks on and if the pipes get cold.