A friend has a 1982 Euro 300TD that keeps blowing a fuse that controls the windows and turn signals. He cannot correlate it to use of the windows or application of brakes or turn signals. I measured current flow through the fuse and it seemed reasonable. I put LEDs in the tail light assy to bring down the base current and it held for a few months.

Now it's blowing again which suggests an intermittent short. Does anybody have suggestions for tracking this down?

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83 300TD, 260,000 miles, aka "Dusty"
6 vehicles, 2 cup holders (both in the dump truck)

there is a bundle of wires that go through the hatch hinge area... I'd start there looking for something intermittent. I don't know if the wiper motor or license plate lights are on the same fuse, but it's a place to start...

I would suggest starting on the ground side of those circuits....starting at the neg battery terminal... make sure all connections are clean and tight...

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Hi
When I had a like problem, I bought a short finder at O'Reilly's ($30?).

It consists of an automatic re-set breaker that you use to replace the fuse that's blowing and a magnetic field meter. The idea is that when power is flowing through a wire it creates a magnetic field that can be seen on the meter as you follow the wire path with the meter - until you get to the short where the magnetic field stops. Of course the automatic breaker keeps breaking and resetting so you have to wait for the reset to continue checking each time.

Once you find where the short is - you then have to open up the harness to look for bare wires - or if the short is in a device of some sort - disconnect and/or replace.
Good Luck,
Joseph

Thanks for the suggestions. I might have found the problem, but it is hard to say if an intermittent problem has been fixed. I thought this was a Euro wagon because of the headlights and side markers on the front fenders. I think I was wrong.

The side markers were after market ad-ons, unless both fenders had been replaced. They were wired into the front turn signals with aftermarket wire crimps. The wires were run through the pocket where the hood hinge drops into, then the wires went through a hole in the fender without a grommet. Both wires on one side had been crushed by the hood hinge. I taped them up and moved them to the side. We'll see if this was the problem.

I don't like this car. My friend bought it off eBay for top dollar. He does not know cars at all. He gave me his old 300TD because the interior was trashed and his mechanic could not get it going (said it needed a $1200 IP but really needed glow plugs and a primer pump). He bought the replacement 300TD because it had a cheap overspray paint job, shiny wheels from a later Mercedes, euro headlights, and a decent interior. I went to change the air filter for him when he got it, and it was missing... A shiny piece of neglected junk.

I'll cross my fingers on the short circuit repair.

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83 300TD, 260,000 miles, aka "Dusty"
6 vehicles, 2 cup holders (both in the dump truck)