So my gauges and dash lights stopped working on my 1990 240dl and my battery light came on today. Anyone know what the problem would be? The connection to my battery is clean and connected well.

 

bad ground behind the dashboard, perhaps?

if the alternator light is on, take a volt meter, and measure the voltage at the battery while the engine is off and again with it running, the running voltage should be about 1 volt higher (maybe 13.8V instead of 12.6V, something like that), if thats the case, the alternator is working ok.

 

About how much are volt meters? The only thing I'm really electrically inclined at is installing radios and speakers. Other than that I would be lost behind the dash looking for bad ground wires.

 

you can get a cheap chinese digital multimeter for like $19 or something stupid nowdays. I usually like to get a little bit better one for maybe twice that.

 

Well I started my car last night and everything was working again and the alternator light doesn't cut on now. I've tightened all connecting wires from the battery, starter, and alternator. I may have a bad wire somewhere. I'm hoping it doesn't happen again. Thanks for the info Pierce.

 

I had a similar problem that would happen intermittently on my '90 240. It never happened to me but it happened to both my son and my wife when they were driving the car. Basically the whole instrument cluster went dead (although they didn't mention anything specific about the battery light). One night when it happened to my son, he was driving home from work and drained the battery down entirely.

I pulled the cluster out and inspected all of the connections. They were discolored and covered with grease (it didn't look like dielectric grease either). I degreased and cleaned up all of the connections and haven't had any problems with it since.

Good luck