420 SEL Wiring Harness Mixup
 

Dear All,
I am in deep and I hope you all can help. I just had a small shop replace my engine after rebuilding my transmission (long story, trust me) and it idles around 1500-2000 rpm. I checked the listed threads on the Idle Control Valve and the Idle Control Unit already. I suspect a misconnected wiring harness. I am more familiar with 240D diesels, but I can follow directions.

Actions to date:

(1) I cleaned the ICV and lubed with ATF. If I apply 9 volts to the valve with a transistor battery it will kill the engine.
(2) When I plug in the ICV, the aux fans come on, even when engine is cold. If I unplug the aux fans I can hear a rely in the fuse box click when I plug in the ICV connector.
(3) I checked the OVP fuse (10 amp). It is ok.

Before I go to another independent shop and open my wallet some more, what else can I check for and does my diagnosis of a mixed up harness sound right?

Thanks

CarolinaBenz

There's not much of a wiring harness for that engine since it's primarily CIS fuel injection. That being said, try this link for your car.

http://mb.braingears.com/126_DISC2/program/engine_420SEL.htm

Pick 07.3 for the CIS-E system and begin your testing.

Check the wiring harness for a 'set' in a particular direction. That would indicate if a connector is in the right socket/plug.

Thanks for Info.
 

I will go through the harness. Thanks for the technical input.