1991 350 SDL Glow Plug Dash Light Problem - PeachParts Mercedes-Benz Forum

newptken · #1 07-23-2006, 04:59 AM

Just replaced all glow plugs in this SDL with 76000 miles, haven't had car
but a few weeks, it appeared that the plugs that came out were new. The
dash light works properly on occasion but other times it doesn't come on and
will come on after car is cranked, it will stay on for a few seconds and go
off.
Any help will be greatly appreciated.
Thanks in advance,
Frank

andmoon · #2 07-23-2006, 08:19 AM

I'd start w/ the ignition switch...my 90 did similar...though my gp light never came on once the car started.

newptken · #3 07-27-2006, 10:11 AM

Quote:

Originally Posted by andmoon

I'd start w/ the ignition switch...my 90 did similar...though my gp light never came on once the car started.

I took to Mercedes dealer, replaced relay($157 plus small labor) which corrected my problem, dash light works fine.
Thanks,
Frank

andmoon · #4 07-27-2006, 10:22 AM

Which relay did they replace?
OVP?

brandlj · #5 07-27-2006, 10:27 AM

There is a black box relay that sits on the drivers side inner fender that is the glow plug relay. It sounds like your relay is going bad. There is an actual protocol to troubleshoot the relay which will allow you to discern if the problem is the relay, the light bulb itself, or the glow plugs.
This test protocol is in the CD repair manual for you car that can be purchased from Mercedes Benz Classic Center for $20.00.

John