On my 300D the compressor system works by putting 12 v to the pressure switch circuit. I have been doing some troubleshooting and have found that I am not getting power through this circuit. Has anyone got a schematic that shows where the power is supplied from that they could fax to me? Should one side of the evap temp sensor have power (the black/red wire maybe)? Does the pushbutton console supply the 12 volt power for this circuit? The schematic I have does not go into enough detail to indicate where this circuit "ends". It just shows one end which is at the Klima relay. I am running a new Klima relay.
thanks,
Jim
'85 300D
'95 E320
'97 CRV

Behind the glove box and the vent pipe there is an early over-voltage relay. Check the fuse and replace it.

Good luck.

__________________
Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

Thanks Donnie,
I went out and pulled it out and the fuse looked good and tested good. I put the Fluke on the relay poles that are shown to be accross the fuse (with the fuse installed) and I did not have a complete circuit. Based on what is printed on the side of the relay it looks like there is a diode in this loop. Have you ever seen one of these relays fail? It got too dark on me to do much more roubleshooting tonite.

For right now I have disconnected the black/red wire from the evap temp sensor and am supplying power to this circuit through a 5 amp fuse and a toggle switch. I use this to turn the compressor on and off while maintaining the protection offered by the evap temp sensor and the freon pressure sensor to shut the compressor down if either of these items get out of spec. Can the push button console cause this type of problem?

I would like to eventually fix it "right". Where can I get a good wiring diagram for this vehicle? Are they available in Partsshop.com?

thanks
Jim
'85 300D
'95 E320
'97 CRV