Hey Gang. i was having problems with my 88 300 E. one of which is that the Radio wont turn on, but the LED wont turn off!
It stays in a suspended state of jibberish.
E IO U &
something like that.
I pull the fuse and the led goes out when the doors are closed but comes back on when the doors are open! Kinda sucks too cause the fuse is hooked to the hazard lights and some interior lights.

The battery was draining as well. When I pulled and replaced the battery, everything was fine for 2 weeks, the radio worked as it should. Now the problem is back.
is it a short to ground somewhere, maybe a incy tincy one?
if it was could it be anywhere or is it in the radio circuit?

I have disconnected the key buzzer at the relay, but i don't think that would affect it. Could it be a short in the antenna?
I have pulled the old motorized one and replaced it with a canadian tire special!
is it because the antenna is not wired to the chasis anymore?
any thoughts would be appreciated.
T

 

one more thing. The bulb replacement light comes on for about 2 minutes after i turn on the lights. then goes out again. but no lights are blown.
any thoughts?

 

The jibberish isn't a good sign -- seems unlikely that something external would be causing the odd behavior, but I suppose it's possible that the radio doesn't play nice with your battery drain problem. Unless the jibberish is an error code by chance? I did a little searching and it does sound like the becker radios (assuming that's what you have) do put out error codes. With the jibberish starting with an E it makes me wonder.

Try looking at these posts and do some additional searching: Becker Error at EverythingBenz

Can you pull the radio out completely and do you still have the draining problem? Maybe try that and work on one thing at a time. Eliminate the radio as a potential cause and then when the battery situation is stable, pop it back in and tackle the radio.

 

I have an 89 300E and soon after I bought it had a battery drain as you describe. It turned out to be a bad alternator, I could put a charger on the car and charge the battery. Then put the battery minder for the motorcycle on it and the battery would drain down with the minder plugged in. Sometimes my check engine light comes on after the engine is turned off. The mechanic checked it and since it did not do it while he was working on it and these old style systems do not save faults there is nothing to check.