Low Battery, Maybe.
 

1984 300SD
Went to start car in the morning, and it acted like I had a low batt. Jumped the car and still as if the battery was low and would not let the car start. took out the battery and had a loud test done. Was told that the batt. was good. bought and changed out starter thinking it might be bad. Changed it out in a very bad rain storm that day. got done and the car now when you turn the key to heat the glow plugs. I get no dash lights to tell that the glow plugs are heating or that power is on, the only light that comes on is the parking brake light ind. and the starter will not turn over. Weather has bin not so good and work so I have not looked at anything else. Any help on what might be wrong and what I might look for and check would be great. Thanks All Bob

I'm thinking bad battery cable, bad connection at the terminals, or bad ground.

Thanks it will look at that this week end. when it get back to looking at my problem.

Grounding Strap from Engine to Chassis
 

'Will look like Flat,"Braided" Cable !!!!
(All Connections...Clean and Tight!)

Electrical portion of the Ignition Switch?

Thanks, It was a bad Ground. You people Rock. Thanks again. Bob

i'm having the same problem not staying charged
 

I also am having problem with my ML 350 not staying charge i even went an brought a new battery an still its not stayin charge . I even disconnected the battery cable to see if it would cut off but it stay rrunning so i m thinking its not my alternator what do you think it can be i have no idea anymore i hate to go an buy a alternator and its not the problem......

DMM Tells ALL
 

Either HF or Sears usually have a DMM on Sale for Ridiculously Low Price.

If you hook one up between the Battery's Positive pole and the Alternator
(If your Chassis is wired that way)It'll show you whether the Alt is Draining
the Battery.

First look at the Trunk Light! (Known to stay on!)