Well, I thought I finally figured it all out. One by one the plugs came out and were replaced, cleaned my connections real nice, and finally I am rid of the blinking glow plug light...

So now, every so often when I go to start the car, the glow plug light blinks for a second then goes out. If I crank, it is like there is no glow happening. If I just turn the key off and try again, I get the solid glow light and she starts as she should.

Any ideas what in the world is going on here?

__________________
Think Alternative Energy!
300CD '80 (now gone but not forgotten...)

Do you have the relay behind the left headlight?

Yes the relay is near the headlight..

__________________
Think Alternative Energy!
300CD '80 (now gone but not forgotten...)

If your relay has a cover still...remove it and find the (80 amp?) Aluminum strip
fuse secured by two Phillips head screws.
These fuses are prone to almost microscopic cracks...looks good to the eye
but fails the Multimeter continuity test.
Remove fuse(sometimes this will allow the fault to become more evident) Test
for continuity with DMM.
I'd snag a new fuse,of the appropriate amperage, from the Dealer ...you will
want to carry one in the glove box as a spare...before the test...that way
you're ready no matter what.


If your relay is an all metal Aluminum type relay...I don't know what to tell you.

Attached Thumbnails

 

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'84 300SD sold
124.128

ah, I did check that fuse for continuity per DieselGiant instructions; but did not remove and check. Good idea...

__________________
Think Alternative Energy!
300CD '80 (now gone but not forgotten...)

In addition to checking the strip fuse, it might be worthwhile to clean the contacts on the relay itself. (Open the box by removing the four screws in the corners.) The problem could also be a poor connection from the ignition switch wiring. But the most probable issue is with the solid state portion of the relay controller.