300E electrical problem
 

Hello All,

Just notice that when I have the door open (vehicle stopped, engine off) the overhead light gets dimmer and brighter in direct correlation with the seatbelt warning sign flashing on and off. I just replaced the battery with a 49-82 (big, new; lots of cold cranking amps), but the alternator is 200,000 miles old. Any ideas? Is this normal?

Thanks,
Gebhard

Had a similar problem, except my interior lights would flicker somewhat and dim gradually. It was worn brushes in my alternator. Cheap and a 5 minute installation for new ones. Works perfectly now. I'd test to see if your alternator is charging properly. There's plenty of info on how to do so in the archives here. Good luck!

That sounds normal. All 3 of my cars do it. The dimming is not significant, but noticable.

Guess I'll leave it be.

Thanks!

I have a flickering problem that just started today. The flickering was very noticable. The headlights and dash lights had the appearance of a highway patrol when the headlights flash off and on. I'm pretty sure its the alternator as it only does it when the engine is running and seems to speed up with engine speed. It didn't do it the last time I drove it two days ago.
I had the sme problem before that the lights would flicker as was solved by replacing the alternator. The alternator was charging steady at around 14 volts so I was puzzled. I was told the diodes go bad as cause spikes that are not detected by a voltmeter but show up as other symptons as flickering lights.
I will keepyou posted.