924Board.org

doiron_dancer75 · Posted: Thu May 14, 2009 11:07 pm Post subject: Electrical problem

So this past week we had to change my ignition switch in the 924. But around a week before we changed it a wire from my coil to the fuse box burned. The wire may have burned further in the fuse box, but the fuses in front of it seem fine. Does anyone know what would cause that wire to catch fire? Any help would be great.

Thanks

huckster · Joined: 22 Dec 2006 Posts: 115 Location: Burnaby B.C.

I do not have any specific expertize with that wire but I had enough electrical gremlins that I took my fuse box apart and found lots of shorts due to rusting inside. Allso the grounds behind the fusebox will cause lots of problems if they are dirty.
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ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

High resistance due to aged wires can cause heat, enough to melt the shielding and even cause it to smoke. Or a short to ground prior to the fuse.

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doiron_dancer75 · Posted: Fri May 15, 2009 10:04 am Post subject:

Thank you, my father will be checking those suggestions tomorrow when he's done work. I'll post tomorrow with any further info.

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

Your car has one or two resistor bolted to the sides of the coil (depends on the model year of the car). Could be a coil to resistor wire rubbed itself bare, and shorted to the coil mounting bracket or bolts and nuts.

That's where I would start looking.

doiron_dancer75 · Posted: Fri May 15, 2009 11:57 pm Post subject:

The car is a 1979 924. I'll get my father to check it out as soon as he gets home from work today.

Scorpio · Posted: Sat May 16, 2009 9:19 am Post subject:

check youre using correct fuses...mine were all mixed up from PO...fuse should be the first thing to melt in a circuit unless a higher then normal fuse is being used as a bandaid
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doiron_dancer75 · Posted: Sat May 16, 2009 11:55 pm Post subject:

Ok so me and my dad checked everything out yesterday, turns out my alternator let go. We had it rebuilt last summer, and I guess whenever it let go that one wire burned.

John Brown · Joined: 07 Nov 2002 Posts: 903 Location: Leesburg VA

Somewhere, years ago?, I posted pictures of, I think, Plug A on the back of the fuse box. A17 (??) had over the years burnt out the plastic surrounding that pin simply from the continued heat at the junction. And I saw 2 or 3 fuse boxes like that. May be wrong about the exact pin number. Anyway, A17 is the power to the coil.

Point being that there are several circuits which are marginal especially over time. Heat begets corrosion which begets more heat .... Or is it corrosion begets heat which begets ....
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