1995 E300D - No A/C in the rain - PeachParts Mercedes-Benz Forum

jgauto · #1 08-14-2003, 11:42 AM

I'm having a problem with my A/C when the vehicle gets wet the A/C shuts off. This usually happens in heavy rain and after washing to car.

The belt and idler pulley was replaced, but the problems still remains.

Any ideas?

Thanks in advance!

#2 08-14-2003, 12:58 PM

It may be the tensioner. If the tension is inadequate the belt will slip in the rain. Replacing the idler pulley will not increase tension. Only replacing a bad tensioner will restore tension.

Good luck,

jcyuhn · #3 08-14-2003, 01:33 PM

Is the plastic splash panel below the engine present, or missing? The main function of this panel is to keep water splash off the serpentine belt in wet weather. If the belt gets wet, it slips. If it slips, the a/c compressor is cut off until the car is restarted.

The secondary function of the splash panel is to keep m104 oil leaks off your garage floor

- JimY

jgauto · #4 08-14-2003, 02:04 PM

The splash panel is present, but I don't think the tensioner was replaced. I will try the tensioner replacement.

Thanks!!

jgauto · #5 08-25-2003, 10:54 AM

I'm still having problems with my A/C. I washed it this weekend and the A/C wouldn't work for about 20 minutes.

The following items have been replaced:
serpentine belt
tensioner pulley/lever
a/c speed relay $$$

Is there something around the windshield area that I can check? This is the only area I can see thats get wet when you wash the car. The splash shield under the car is in place.

Any help is appreciated.

#6 08-25-2003, 07:44 PM

Hi,
When you say the A/C does not work, do you mean that the compressor stops working or the blower stops blowing, or both?
If the compressor stops and air is still coming out of the vents inside the car, then it is likely that you are geting water on the belt as the previous replies stated. If you aren't getting air out of the vents after washing, try rinsing a little less dilligently!
On my 95 E300D, very little water on the belt resulted in no A/C cooling due to slippage.
Steve

J.HIDALGO · #7 08-25-2003, 09:44 PM

check if it is wet back there. Otherwise, it has to be a loose belt.

jgauto · #8 09-02-2003, 07:49 AM

I tackled my A/C problem yesterday and solved it. I traced the wires from the compressor to a connector behind the battery. It turns out that the bundle of wires had been exposed to battery acid and were minus their insulation......So when I washed the car or drove in the rain the bundle of wires got wet and no A/C.

Mark Herzig · #9 09-02-2003, 11:20 AM

I have exactly the same problem with my '95 300D! Last week I had the car in for brake pad replacements and after they washed the engine, the AC stopped cooling. The compressor would kick off after about 2 seconds. After all dried out, it was OK.

I first experienced it after washing my car a few months ago and then in an extremely heavy rain fall. There is a panel in the back of the engine compartment , passenger side, that houses a lot of wiring that was sourced to be the problem when wet...

#10 09-02-2003, 03:43 PM

The test for the serpentine belt saving circuitry on a 60x diesel engine is to spray the fan belt with water with the AC running. That WILL disable the AC compressor clutch if the circuitry is working as it should work! The AC compressor should not restart until the engine is shut off and restarted. If the belt tension is inadequate (spring weak) OR the belt load is excessive (power steering pump load or alternator excessive OR the AC compressor marginal) or the AC compressor clutch slips very much (oil or grease on it or the gap too wide) the compressor clutch WILL shut down whenever the compressor speed and the exgine speed deviate more than the allowed amount (about 25% as I recall). If you've removed the sound shields covering the bottom of the engine compartment you greatly increase the chance of the compressor shutting off in wet weather.

Marshall

G-Benz · #11 09-02-2003, 04:58 PM

Interesting topic...

Had the same thing happen to my (non-diesel) 300E.

Hosed off engine one day and that afternoon, no A/C (compressor wouldn't cycle). All was well the next day until I drove in a heavy rainstorm and then again, no A/C.

Never happened again since. I'm reluctant to wash the engine again...well, at least not until the dog days of summer are over!