Just finished putting my new fuel system in and when testing the in tank pump discovered a small leak due to a improper AN type fitting. Fixed it and when doing the leak test found the leak was fixed but after about one minute, I noticed what appeared to be either vapor or smoke. It went away and then I smelled hot electric wire so shut everything down immediately, grabbed the fire extinguisher and started looking for a melted or smoking wire. I was on the lift so had good access to everything. I checked every wire under the car and in the engine compartment including all the new wires for the electric fuel pump and found none of them hot or even warm. Nothing melted, discolored or out of the ordinary. The next day I checked them all again and today looked one more time. I hesitate to power up again until I find the wire(s) but may not be able to find it without powering up. Anything I may have missed or suggestions? Guess I'll get my neighbor to come over and turn the key on while I look under the car with the extinguisher in hand.

 

Double check what ever mods/additions you installed recently. Then power it up while concentrating your attention to those areas. Leave the battery terminal loose enough so you can disconnect it quickly if there is an issue.

 

I think that is the best option. Just can't stand electrical fires, they move so fast...

 

Been there and understand.

 

check first, the last thing altered.

Check current draw?

Pull all fuses and insert one at a time?

The fuses are supposed to prevent wires becoming heaters, but any portion between battery and first fuse is susceptible.

 

Also, maybe you leaned on something anywhere on the car while you were working. Sometimes that "disturbs" a wire, even inside the harness, and causes a short. It's a long shot, but I've had it happen. The odd thing is that, on my Mercedes once the smoldering wire in the dash cooled down, it didn't short again, even though I didn't really find anything, except for jiggling a loose wire inside the trunk lid. Obviously, I don't have much confidence in that "repair", but it's been over a year and the problem hasn't come up again.

Tom