M119/W124 Lower engine harness
 

What exactly does the lower engine harness attach to/control on an M119/W124? I know it has to do with the alternator/charging system but there are other sensors it plugs to as well from what I understand. I'm tracking down some real nighmare symptoms, I've done everything to correct but still persist.. I'm grasping for straws. Any info appreciated.

Did you ever figure this out? I'm trying to resolve a 'bogging' issue - runs fine at light throttle and bogs (slows) with heavy throttle.

New upper harness, rebuilt ETA, tested two EGAS modules, checked fuel, fuel pump, fuel pressure, fuel filter, fuel quality, cats, replaced throttle switch and still nothing has been resolved.

Desperate in Austin.

In addition to the alternator and starter, the lower harness on my E420 runs to the oil quantity indicator and the oil pressure indicator. That's it.

Which makes me wonder why the suggestion to replace in my case...

Why would that cause a car to 'bog' (slow down when heavy throttle is applied).