Idiot lights glowing.
 

Sorry if this is a repeat question, did try a quick search first.

I have just replaced the alternator on my 300CE. It is now charging but the idiot lights glow constantly. I want to be sure of my facts before trying to return the unit under warranty. Bad ground? That was not an issue before. Any suggestions welcome. Thanks, Patrick.

Might be a reach but try...
 

Might be a reach but try changing the OVP. Sometimes these units malfunction and cause all sort of problems.

jrmd01@yahoo.com

Which idiot lights? Just the alternator light?

If so, either a bad alternator (lamp shouldn't light it it's charging at all) or a loose connection on the alternator.

Peter

All the idiot lights in the gauge cluster inc the low fuel light. The battery light is a little brighter but none light up full brightness. The glow diminishes as the revs increase but never go out completely.

I had the same problem 2 weeks ago when I replaced the alternator on my '90 300TE. It turned out to be a bad rebuilt. Phil sent me a replacement the next day- problem solved!!
Dan in SoCal

Dud diode
 

Same problem as Dan's. Turns out to be a faulty alternator, will have another tomorrow, no arguement. Thanks for the replys.

Yeah, except what happened to the road test? The techs should have caught this before letting it go out of the shop. What a time killer for you. Was this at a dealer?

Fitted it myself. Just a little annoying to have to do the job twice.

So you replaced the alternator to fix the problem? Would replacing the voltage regulator maybe fix the problem? Isn't that the piece that goes into the back of the alternator or is that the brushes?
Thanks
David

I don't know for sure about the brushes, but I do know when my Voltage Regulator was bad, I had the reverse -- no idiot lights, even in the test sequesnce (key position 2).

Hi David,
I could have replaced the diode pack but the alternator is a fresh rebuild and under warranty.

Picked up the replacement recon alternator, fitted it today and all is well.