rare open circuit

September 18, 2010, 09:25:12 AM

Wife calls me up and says she tried to start the 20th and smoke came from the driver side engine bay.
being on a work trip, i told her not to worry, I deal with it later.

I get in and attempt the start and yep, it wont start. i had a few operational circuits like chime and such but most everything was down.

i went up front and did a visual around the battery but didnt see anything.
looked at multi-leg harness coming from the starter relay and everything seemed normal.

i turned the key on again and did not hear the eec relay or the fuel pump so im figuring this is a pretty hard failure.

go back up front and focus on primary power distribution of the starter relay and get busy with my meter.

with the key on, i back probe the very first connector leading from the starter relay that has some yellow wires , brown orange and the transmission neutral wire.
one lead had no power going to i which was impossible i thought since all these yellow and the brown/org tie to the same point.
on closer inspection, I found one of the the brown / orange wires had power on one side of a splice but no power after the second splice down. This was measuring bascially on one of the fuse links.

I physically felt the wire and noticed i was able to bend it really easy in one spot. I fiddled in this area and found the wire was broke inside the insulation but the insulation looked like new.

there should have been a melted area in proximity to the open but all looked well.

fixed it right and then all worked fine.

still, the visual smoke my wife saw bugs me. If the smoke didnt come from the fuse link , then what else is lurking waitnig to burn.

after all, a fuse link burns when something goes wrong, so i actually didnt find the problem, i repaired the fuse. this kinda goes against my better judgement but are there any ideas people have come up with to figure out why the fuse links have blown?

does anyone have load data or clamp on ampacity data with all ckts ingaged?

looking for ampacity data on the 5.0 fuse links.

I can do one up quickly on my end to compare.
I figure if I show more current draw, the difference would be if you have less features than my 20th. idealy, someone equiped with similair features or same options can get readings to post up.