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!tom · Posted: Fri Jan 01, 2010 9:39 am Post subject: Now I've done it! (melted wiring)

Well, I was trying to weld up the crack in the firewall that I believe cracks due to the clutch pedal. It's right around the wiper motor.

I was hunting for a good place to put the ground, so I figured the big hunk of metal that the wiper motor is mounted to would be good enough.

My first hint should have been that I kept on having to crank up the heat on the welder, but it wasn't till I saw the inside of the car full of smoke when I thought to take a look.

I guess there wasn't that good of a ground after all, since I think I was grounding through the wiper motor wiring harness. What used to be a nice looking wire (I'm assuming brown) is now a bare piece of wire that had melted into the carpeting in the car under the dash. Also, the right front turn signal and corner marker, as well as the right rear marker light are always on.

I'm not looking forward to this.

I've disconnected the battery, and I guess I'll pull the seat tomorrow. It's raining out, and not forecast to stop 'till May sometime.

Any suggestions? The fact those lights have turned on scares me. That means I've melted through somewhere to an always hot wire.
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78 924 NA
5-lug

Imafordguy · Joined: 06 Dec 2009 Posts: 189 Location: Eugene Or.

Any suggestions?
Buy a case of beer for tonight... Wake up in the afternoon and buy a mess of wire, another case of beer, and an instant shade or a wetsuit.

Sorry... That really sucks. Is the carpet burnt? Hope you can salvage everything.
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81 Porsche 924
84 Porsche 944(parting it)
66 Ford f100
66 AC cobra kit car(major project)
64 ford f100 (429 SCJ)
62 Studebaker golden hawk gt
61 baja bug (with bad opel 1.8, looking at ford 2.3 turbo to flovo)

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Ouch. Not fun. I would remove the steering wheel, the column surround, all three main gauges, the gauge surround, and start inspecting from there. Be prepared to remove the aux fuse panel, and possibly drop and lower the main fuse block. Hopefully the damage is isolated to a single circuit. My concern is that the wiring through the stalk and surround may have conducted the heat, and there's a buttload of stuff going thru there for the turn indicators and such. This is why removing the steering wheel and surround will help, because you're going to want to carefully inspect everything in the steering column.

I might have enough bits and pieces of harness for you to perform some surgery. Once you tear into it and know what your issues are, you'll be able to determine if you can get by with just splicing in new sections of wire, or if you're going to need harnesses. Good luck.
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erstwhile owner of just about every 924 variant ever made

!tom · Posted: Fri Jan 01, 2010 10:25 am Post subject:

Min · Posted: Fri Jan 01, 2010 10:40 am Post subject:

ack, that sucks man

chasing burnt wires is always a major pain

.

Min
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Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting.

Imafordguy · Joined: 06 Dec 2009 Posts: 189 Location: Eugene Or.

I had a 89 vw fox, at least 11 years ago, the ex-wife totaled it out two weeks after I resurected it.

I was a dumbass and ripped out of the drive in reverse. I was mad at the ex, We were engaged at that time, and late to leave for work. When I made my turn and slammed on the brakes the battery that was not tied down tipped back and grounded out on the hood. I rushed to disconnect the battery as smoke traveled across the dash and engine compartment.

I had to pull a fuse box and wiring harness out of a junk yard, That was the least painful part of that chore. Dash had to come out the car most all the interior infact. Did new struts and lifters while it was down. Totaled two weeks later which was the day we returned from our honeymoon. Good times
_________________
81 Porsche 924
84 Porsche 944(parting it)
66 Ford f100
66 AC cobra kit car(major project)
64 ford f100 (429 SCJ)
62 Studebaker golden hawk gt
61 baja bug (with bad opel 1.8, looking at ford 2.3 turbo to flovo)

!tom · Posted: Fri Jan 01, 2010 8:22 pm Post subject:

Yah. Great thing about all this is the weld absolutely sucks because I couldn't get enough current through the wiper motor wiring harness. The wiper harness crunches when you flex it now. . .

I think I've learned my lesson about ensuring a good ground for welding.
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78 924 NA
5-lug

924aussie · Posted: Sat Jan 02, 2010 2:45 am Post subject:

The good news is that you can still chase down most of the coloured wires , I know as I have had to get a few roles of each when I couldnt get a harness.

Alan
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green 924 .. 1980 rego 924PSH
1998 Mopar Neon ... sick
2003 Challenger / Montery 4WD
1995 Hyundai Scoupe ... sold
1998 Nissan Silvia ... sons back from OS he has taken it
BIG BLOODY MOTORHOME 300zx Sold
1980 Fire truck Sold

Joes924Racer · Posted: Sat Jan 09, 2010 4:32 pm Post subject:

That is a bummer , Ive been there.. wires go up like a fuse on a 4 th of july firework .. and lots of smoke & some hissing as the plastic melts of if theres enough juice.. the wires get stuck together.. and bare, the plastic burns off leaving brittle carnage. Best thing to do is snip & splice.
Good luck, What pop a beer sit in the car contmplating on where to start.
pop another ...jus watch out for pop,pop,pop .. pop now what.
No really it just takes a little thought and do one component at a time.

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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

!tom · Posted: Thu Jan 21, 2010 6:33 pm Post subject:

Well, it finally stopped raining, so I took an opportunity to look at the car.

The picture on the left shows how the ground wire burnt all of its insulation off as soon as it left the black wiring conduit.

The picture on the right shows how the insulation is blistered a bit on the one ground wire at the connector end.

There are no shorts in the wiring harness. I should be able to just hook things back up and it should work.

However, that's not a very elegant solution.

My options are:

Hook it back up, as is
Trim back the housing and splice a new section of ground wire in to replace the section with no insulation
Cut the black housing off, as it appears as though the wire inside caused it to melt a little bit in places, and there's no way it's pulling apart. Then, replace the cooked ground wire, and cover the entire harness with a new piece of heatshrink.
Create an entirely new harness, using whatever colour wires I have on hand

I'm leaning towards either 2 or 3.

There is something a bit odd about this wiring harness. There's two ground wires as you can see that connect to the center terminal. One (the big one) leads to the impossible-to-get-to ground above the fuse/relay panel. The other goes to the wiring loom that enters the engine bay. So, it's impossible to remove the wiper motor harness from the car without cutting wires unless you remove the harness that goes through the firewall into the engine bay as well. I have no idea why that other wire doesn't continue directly to the grounds. I'm tempted to cut it off so I can remove the harness, then splice in a short section of wire (if I must) and connect it directly to the ground terminal.

Thoughts?
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78 924 NA
5-lug

PORSCHEV · Posted: Thu Jan 21, 2010 9:24 pm Post subject:

The pictures didn't load. I would run new ground wires to the wiper motor if that is all that is burnt.
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1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Pix didn't load...
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erstwhile owner of just about every 924 variant ever made

Imafordguy · Joined: 06 Dec 2009 Posts: 189 Location: Eugene Or.

I can see the pics... I would say go with number 3.

I was expecting to see alot of damage. Strip back a few inches of the harness wrap, continue removing an inch or two at a time till you expose 3-4 inches of un burnt plyible wire. Inspect all the wires in that harness for damage from the heat. Splice needed leads, and replace wrap with black tape. No need to try to shrink wrap the harness, tape will do. I would suggest solder and shrink wrap splicing.
_________________
81 Porsche 924
84 Porsche 944(parting it)
66 Ford f100
66 AC cobra kit car(major project)
64 ford f100 (429 SCJ)
62 Studebaker golden hawk gt
61 baja bug (with bad opel 1.8, looking at ford 2.3 turbo to flovo)

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

I can see the pix now. I would opt for either #3 or #4. In either case, I would make a longitudinal cut in outer harness sleeve in order to inspect the wiring a bit further up- and downstream. You may find more damage hidden in the sleeve that could cause nasty issues later. I would definitely be splicing in new wire. It might also be a good idea to make sure there's not too much resistance on those wires now, check with an Ohm meter.
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erstwhile owner of just about every 924 variant ever made

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Cheese solution: Wire itself looks fine, get some "liquid electrical tape" at FLAPS and seal it up. . .always preferable to crimping in new sections, IMO.

I used a bunch of this stuff to seal up electrical connections on Chumpy (the ones that were gonna get rained on running with no hatch - DOH), and it worked extremely well.

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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3