W110 - Short Blowing Fuse - Fuel Indicator

[dingjob]

I was driving my '65 W110 the other day and noticed my fuel indicator magically stopped working in the middle of a cruise. Everything else seem fine, so I didn't worry about it till I got home. Noticed fuse #4 blew. Tried replacing it, turned ignition on and pop. Fuse #4 powers fuel indicator, backup lights, turn signals. Seeing how the backup lights and turn signals aren't really given power until I put the car in reverse or turn the turn signal, I assumed it was fuel indicator related.

I went into the trunk and unplugged the fuel sending unit and replaced the fuse again and it still popped. I was really hoping that would be the problem and it would be simple but of course not. If you had to bet, where do you look to next? Something fuel indicator related behind the instrument pod? Or is it more likely related to backup lights or turn signals?

Any other tips or tricks to troubleshoot this? I've seen some hook up test light to show short to ground but never tried this personally.

Thanks.

[dingjob]

Bumping this to see if anyone has experienced something similar.

I've continued troubleshooting by unhooking fuel sending unit, removed taillight connectors, took bulbs out of the front indicators and it's still blowing once ignition is turned on.

[RobertFini]

Originally Posted by dingjob

Bumping this to see if anyone has experienced something similar.

I've continued troubleshooting by unhooking fuel sending unit, removed taillight connectors, took bulbs out of the front indicators and it's still blowing once ignition is turned on.

I would start looking for wires on which the insulation is rubbed (or chewed) through, allowing a short circuit from power to ground.

[dingjob]

Using service manuals I was able to trace it down to the blinker relay or flash signal mechanism as I've seen it called. This is located in the hood right next to the fuse box. It was shorting to ground and causing the #4 fuse to blow. I wanted to post this in case someone stumbles upon a similar problem. Naturally I found all of this after tearing apart the steering column and turn signals but none the less it's fixed. Thanks for the reply.

[RobertFini]

Thanks for reporting back on the culprit - glad you were able to find it.