Resurrecting a 72, got some burnt wiring I'm trying to ID

[71swb302]

Picked up a rolling 72 swb that someone abused (Heated up front springs trying to lower) but otherwise solid cab. Got a donor 76 that I canabilized the motor/trans disc brakes ps. Project was going along great until I noticed some burnt wiring off ignition sw and drivers door jamb. Wasn't much left of the wire insulation from ignition sw, I'm guessing it was red/green to bat on solenoid but wanted to make sure. It was only wire on ignition sw that had two wires on same connector... Other wire was yellow.

Pulled this pigtail from a 71 at boneyard... might just rewire original, this shows what wire I'm talking about at least, on this harness it looks like its paired with pink wire though...

ignitionswitch.jpg

Second issue. What is this for and what could have caused these to melt too? (Different issue possibility) I'm assuming some sort of door buzzer? Thing that confused me is it appears to run in the dash and out the firewall into engine comparment

doorjamb.jpg

Lastly (Hopefully) : Found this hanging under dash, what is it and where does it go? If its a neutral saftey sw I didn't see anywhere to mount it

neutsw.jpg

[mk]

The last pic is a neutral safety/backup light switch and it mounts on the top side of the lower column before the firewall with two screws. The second pic is a resistor that's part of the emission system. Wires go to a solenoid on the valve cover if system is complete. If not I wouldn't worry about it.

mike

[71swb302]

Awesome! Thanks Mike.

I removed insturment cluster and harness wrapping to trace down wire some more and make sure there wasnt any more damage, the wire goes to a union (don't think its a fusable link, if it was it didn't blow) were it turns into what looks like a solid blue wire, on the other side is a green/red wire and red/blue(IIRC) that were unaffected. Following the blue wire it is burnt all the way to the firewall and loops under the hood into what looks like another fusable link then turns into a red (maybe ?) wire. This may all be related to the emission system you were refering to, haven't got all the harness hooked up under the hood and I'm scared to hook up power and do any more damage.

Here is a pic:

dashwiring2.JPG

Thanks -Joe

[mr_josh]

Man, I know where you're coming from. One or some of the many POs of my truck thought that every 12v+ wire would be a good source to tap for some kind of high wattage light. Stuff under my dash looked a lot like yours.

[71swb302]

Luckily it looks like its only this one circuit. The wiring for the emission resistor was isolated and easy to remove. Just got to trace down this circuit and I should be good, rest of wiring looks real good.

[flyboy2610]

That bracket on your doorjamb is for your dome light switch, which you appear to be missing. I am not sure what the little door bell button looking thingy is, though. My '69 doesn't have that.
Sections H and I might prove useful to you: http://www.fordification.com/tech/schematics.htm
Good luck in your search. Wiring problems can be the worst of all to try and fix!!

[71swb302]

Yep. Got that one figured out. I've been trying to study those diagrams but some of the colors werent matching up. Hopefully ill have more time this week. I hooked up a battery to it and doesn't look like anything is grounded. I found I'm not getting 12v to S on solenoid, but power to ignition sw. I'm suspecting to find some funky wiring behind radio wierd thing is its the factory one. Looks like I'm going to be tearing further into the dash. Fun stuff

[basketcase0302]

Like Mike said above..."The second pic is a resistor that's part of the emission system." It looks like your truck is one of the Cali trucks with the emissions control stuff and associated wiring on it. Here's the schematics on the 72's wiring that might help explain it better:
http://www.fordification.com/tech/wiring_1972master.htm
And if memory serves me correctly, (hopefully some of the West Coast guys can chime in here. That door mounted sensor-is just that. It's a temperature sensor that was used to trigger something in the emissions wiring.

I found I'm not getting 12v to S on solenoid,

I'd "revisit" the neutral safety switch. And verify if there is 12 volts leaving the ignition switch.

[71swb302]

Thanks for the help guys.

I've Isolated the damaged wiring as R/G from ignition switch to S5 (splice? doesnt appear to be fuse) and from there the burn wire is B 932 to emissions control solenoids, My main question now is is the B 932 required to power gauge lights? Couldn't really tell from the diagram. The 12v to S is due to a bad neutral switch, ouch those things are pricey, might just bypass it for now =)

[71swb302]

All is well ! Apparently was chasing ghost. Only damage done was for emissions wiring. After removing the burnt wiring, I tried the lights the next day and nothing. They were working before. Was getting 12v but as soon as there was a load it would drop out. Was thinking bad g!round since I just put the front clip back on....was going nuts trying to find issue. Ran a jumper wire straight to dome light from neg on battery. Still nothing. Ended up being corrosion on battery side of solenoid. Cleaned up connection real good and back in business. Must have gotten wet from heavy rains the day before.

Thanks for all the help everyone !

On the positive side of things (no pun intended) at least I have a good understanding of all my wiring now