Hi, I have a 90 740 Turbo. Car has been running great, but all of a sudden 30min ago when I went to turn on the car, it starts then the idiot lights are dim and the battery gauge stays around 10. When usually its in the middle, then after 5 min or so the lights go away and the gauge goes back to normal range. I have a new battery/alternator, I checked the connections they are all tight. The only problem I have is a small wiring problem on the right side with the head lights and the rear lights. But once I tap the front head light it works. Can that problem be the problem I am having with my battery? Please help

TIA

 

Take a Multi-Meter and Put the Positive lead on the big wire on the back of the Alt. Put the black on ground and start it up and see what the voltage is.

The Alt. might be Lagging before kicking in.

 

here is a small update, when I let the car run for 5min then I press the gas pedal to 2krpm. the lights and battery gauge goes back to normal. I am thinking its the alternator belt but I put on a new one last month

 

I still think it might be a Bad Alt.

 

Check the ground running from the case of the alternator to the engine block.

 

Tech was right it was a bad alternator. Bad thing was the old alternator I had one, was less than a yr old. The mechanic did a test, where he took a screwdriver to the alternator and it didnt magnatize. He put a new one on and its all good now, thanks.