1986 300E Fuse #3 Blowing

[brentsmith]

The fuse (#3) for the interior lights and right rear tail lamp is blowing and I have been unable to find the short circuit. So far, I have pulled the instrument cluster and tried to find the ground with the fuse removed. I thought it might be the lamp rheostat, so I cleaned it and resoldered the connection. It held for a few minutes, but then it blew again.

I have the M-B electrical troubleshooting manual, so I do have good wiring diagrams. My next step is to just try to isolate and check each of the loads.

Does anyone out there have some insight into likely short candidates or any troubleshooting shortcuts. I have both an analog and a digital meter and am usually pretty good with electrical problems. This one has me stumped.

Thanks.
Brent Smith
Atlanta, GA
1986 300E 274,000 miles