'85 300SD Today my instrument panel gauges stopped working. Everything just went to "zero". Removed instrument panel to be sure connectors were seated. Couldn't find anything wrong. So called my MB mechanic. He had me test volts at battery while car running, only got 10. He said my alternator is bad. Also, had local auto parts store check, and they said alternator bad also.

So, why does bad alternator cause instruments to stop working? Only clock still works. Even odometer stopped. However, radio still works, lights still work, car runs fine and starts. alternator light and antilock light stay lit for awhile while car running.

Anyone shed some light?

 

well, i checked the fuse again. this time instead of just looking at it to see if blown, i actually took it out. when i did, the little metal end fell off. put a new fuse in and everything works now!! i'm back in business

 

 

the alternator needs that exciter current from the battery indicator lamp in order to start charging.

you have proven them wrong!

welcome to the forum.