Good day,

I have been having some electrical problems with my 1985 740 (manual, normally aspirated).

I had originally thought it was the battery or the charging system but I have since eliminated these items.

I cleaned the terminals and the ground connection to the frame rail on the passenger side.

The problem is intermittant and somewhat bizarre but I think I have it diagnosed.

Sometimes all is OK then other times odd behavior is exhibited. I can jump the car but I have to cable to the lift rings on the engine.

While in the no start condition, any attempt to start the car turns the dash lights off and only the starter solenoid clicks. Jiggling the steering wheel, the shift lever, battery or body also turns some of the dash lights on and off.

I jumped the lift ring to the battery and the car starts. I jump the lift ring to the chassis and the car starts.

I now believe one or more of the engine grounds is bad.

I know about the frame rail ground as I said and I can see an engine ground below the steering pump.

Before I start climbing under/over the engine compartment, I have a questions.

Has anyone seen this behavior?
Where does the negative cable go in addition the the mentioned location?
Where are there ground straps?
Should I look elsewhere?

TIA

jimB