Air Condition Problem On 200 Ml320

[BIGRAY108]

I Have A 2000 Ml320 And Having A Problem With The Air Condition.
The System Has A Full Charge Of R134 And The Compressor Keeps Shutting Of After A Few Minutes Of Use. When It Works It Is Ice Cold. Would Anyone Have An Idea Of What Could Be Wrong?

[rattfink]

could be the aux. cooling fan fuse, if blown, system may work for a while but after pressure gets too high, with no fan to reduce heat, compressor will stop. if the fuse is blown there is a wiring harness update that can handle more amperage and higher fuse rating. check evaporator temp sensor, or bad pressure sensor.

[Chloe Prince]

Thank you for posting these answers.

I have a 2000 ML320. I had filled the Air Conditioning system with a new can of 134a thinking my coolant was low. NOT THE CASE!

Turns out the Blower unit fuse # F44 was Blown out. I replaced this fuse and the fans started working again - HOWEVER, the AC system would not cool. Reading on line, I found out that because I had added another can of coolant, the systems coolant pressure was WAY too high! YIKES!

I measured the system with a gage I picked up an the pressure was at 110lbs +

I blead off the pressure until I got it back down to about 80 - 85 Lbs. The system immediately started cooling again like brand new.

Hope that helps someone else.

-Chloe

[ml320 guy]

Thanks for the tip!

I had just added some 134a refrigerant and I lost all cooling power. After I reduced the pressure, it works great!