81 240d glow plug light
 

I have had trouble with my glow plug relay . Sometimes not working, short glow time ect. Verified that when the light was not on the plugs were not on either. all plugs good, fuse ect. I bought a used relay and installed it, now rhe relay works but the light doesn't light. before I pull the instrument panel I would like to test the circuits to the light from the relay. The question is what wire goes from the relay to the indicator light. I want to test this circuit to see if it is the lamp or the relay. I find it hard to believe that the lamp just happened to burn out when i changed the relay, but you never know.
Jon J
81 240D
325000 mi.

I had a relay that worked but did not power the light. I swapped the bulbs around to find out, but didn't figure out the wire color. Since you have a spare relay now, open the little guy up. You can clean the contacts and it will probably work if nothing is burned up. If nothing else, it's fun to see how it works.

light
 

Yes I opened up my original relay and found burned contacts. I've filed them and will probably switch it back out in the morning. Bu i'd still like to know which one of the wires on the small plug go to the indicator light so I can test the light. I don't want to power up the wrong circuit for fear of letting out the smoke!

Jon J

glow plug ligtht
 

Awww come on you mean no one knows which wire goes to the indicator light?

Jon J
81 240D

Its the Black Wire.....
--If you 'Earth the black-wire with the Ign. on the glow-light will illuminate (The Timer earths this wire to turn on light)

Do this test with the four-pin plug off from the timer.

There is a Brown that should be 'deck'

There is a Purple that should go to the Starter Solenoid cable,

--And another colour I cant remember, but is 'switched Ign +B'....(For some reason, Green rings a bell, but not sure)

There is also a Thick red that goes (More or less) directly to the battery. This is the one that goes to the thick fuse-link at the back of the relay.

The other plug has the four (Or five) connections that go to each glow-plug...

--Just did the whole Glow-Plug installation into a Gasser so I remember the colour-codes:D