Intermittant no-glow on 84SD - Page 2 - PeachParts Mercedes-Benz Forum

funola · #16 06-05-2011, 12:04 AM

Quote:

Originally Posted by layback40

funola,
Not an "Urban legend" It happened to my old 300d. It was the type for the old wire GP's. The outer case had a mall crack in it.
Best you not slur others like that.
It gives the impression that one is trying to hide their own ignorance.

Those Autralian ants must be really dumb.

In other parts of the world ants only go where there is food, not between the jaws of death of heavy duty relay contacts.

So the case had a crack in it? How did that happen? Mercedes is not known to use cheap plastic. Were you drunk when you worked on it and smashed the case and drooled beer all over it?

cmbdiesel · #17 12-13-2011, 06:08 PM

Quote:

Originally Posted by kerry

When it happens, nothing happens. The cabin light does not dim. It might possibly happen two attempts in a row but usually not and it has been happening randomly. No issues with other dash lights.

I filed down the points with an emery board. We'll see if that makes the problem go away.

Hey Kerry, what did you discover with this problem? My 83 SD has just developed the same issue, although it seems to be occurring with more consistency. Typically the glow plug light does not come on, but if I bump the starter, recycle the ignition and bump it again, it seems like they always come on for the third attempt. Glow plugs are new and at last check (3 months ago when all glow plugs were replaced) the fusable link had no cracks.

tangofox007 · #18 12-13-2011, 06:22 PM

Quote:

Originally Posted by cmbdiesel

My 83 SD has just developed the same issue, although it seems to be occurring with more consistency.

Remove the smaller connector from the top of the timer. Check for battery voltage at the terminal that connects to pin 15 on the timer, with the key in the RUN position.

Brian Carlton · #19 12-13-2011, 06:43 PM

Quote:

Originally Posted by funola

So the case had a crack in it? How did that happen? Mercedes is not known to use cheap plastic. Were you drunk when you worked on it and smashed the case and drooled beer all over it?

One of the white hot glow plugs that he tested fell from his grasp, dropped on the case, and melted a hole in the top.

That's how the ants got in.

kerry · #20 12-13-2011, 07:24 PM

Worked ok for a while then the problem began recurring. I got a new relay and it solved the problem.

cmbdiesel · #21 12-14-2011, 05:45 PM

Quote:

Originally Posted by tangofox007

Remove the smaller connector from the top of the timer. Check for battery voltage at the terminal that connects to pin 15 on the timer, with the key in the RUN position.

Thanks Tango, I'll check it tomorrow morning and report back.

layback40 · #22 12-14-2011, 08:12 PM

Quote:

Originally Posted by kerry

Worked ok for a while then the problem began recurring. I got a new relay and it solved the problem.

Sounds like too much of the contact metal had burned away.
you end up with only the bracket material left.

layback40 · #23 12-14-2011, 08:16 PM

Quote:

Originally Posted by funola

Those Autralian ants must be really dumb.

In other parts of the world ants only go where there is food, not between the jaws of death of heavy duty relay contacts.

So the case had a crack in it? How did that happen? Mercedes is not known to use cheap plastic. Were you drunk when you worked on it and smashed the case and drooled beer all over it?

Crack was there long before the car was mine.
Your slur about drinking is well off the mark.

cmbdiesel · #24 12-15-2011, 09:41 AM

Quote:

Originally Posted by tangofox007

Remove the smaller connector from the top of the timer. Check for battery voltage at the terminal that connects to pin 15 on the timer, with the key in the RUN position.

Full battery voltage at pin 15. 12.45v, same as across battery terminals

tangofox007 · #25 12-15-2011, 10:43 AM

Quote:

Originally Posted by cmbdiesel

Full battery voltage at pin 15. 12.45v, same as across battery terminals

Then the problem is not the key switch. Also check for continuity to ground on the brown wire (pin 31) and continuity across the 80 amp fuse.

Have you confirmed that the timer is not starting its sequence (ie: relay does not close) concurrent with the "no light" condition?

cmbdiesel · #26 12-15-2011, 12:59 PM

Quote:

Originally Posted by tangofox007

Then the problem is not the key switch. Also check for continuity to ground on the brown wire (pin 31) and continuity across the 80 amp fuse.

Have you confirmed that the timer is not starting its sequence (ie: relay does not close) concurrent with the "no light" condition?

Continuity on brown wire (31) and across the fusable link. Removed and examined link, no sign of cracks.

When I turn the key and get a no light condition, I am not hearing anything from the relay.

If there were a faulty condition in the key switch, something loose, bad connection etc, then I would not be seeing voltage on pin 15? Possibly I need to engage an assistant who can turn the key back and forth while I watch for voltage...