Electric fire under hood

Hi guys newbie here..
Just got my firs 2door yukon 1992 tbi 350
With the engine just replaced only 24k miles...
Bought it from this lady.. She said cut on fire whe se was driving stoped and someone extinguished the fire...
Parked it.. And decide to sell..
So I went and bought it.
Need some love.. But straight body..
I don't mind fixing the issues just new here... So any ideas where to start.. Just when to get a used engine harness to replace.. Cables distributor cap coil. Module tv cable.. Trhotlle cables. Etc..
But I having issues on how to disconnect the thick conector from the harness at the bottom of the firewall on the passenger side... Any guiding will be appreciated..
I will try to attach some pics here..
Thank you in advance for any help.

Looks like you need a new distributor, and coil, along with all of the burnt wiring. You may be able to pull what you need off of a junk yard truck, but keep on mind that, that will be 30ish years old. Painless wiring may offer a replacement harness.

I'm not saying I want that to happen to my truck, but overall it doesn't look too horrible.

Distributor looks usable if you install a new module, cap, rotor, and perhaps pickup coil. Throttle body seems fine. Brake booster and master cylinder seem untouched.

You need some cables, some wires, some miscellaneous parts like a coil, plug wires, etc.

The big thing would be to try to figure out what started the fire.

I'd be pullin' parts from a Treasure Yard vehicle.

A 1992 model limits you a little bit on which donor trucks you can choose from at the yard. 1991-1992 are the only two years that are direct/near-direct fit. Options on the truck will cause that to vary a bit.

There's no disconnect at the passenger side firewall block - that's simply a grommet, for lack of better term, that screws to the firewall. The actual disconnects are inside the cab where those ends of the harness attach at the ECM and a couple other points, so you just unscrew the firewall block and then follow the wire bundles to where they disconnect.

The driver side on the other hand does indeed disconnect at the firewall, but it seems like it won't, because it is held in place by a thick black tarry goo which protects the connections from moisture intrusion. That is a whole separate harness section from the one on the passenger side so it may not matter in your case unless it is also significantly damaged.

Sticking to 1991-1992 and same engine/trans combo for a donor truck is your best bet. In other words a 1992 8 lug truck (2500hd/3500) would be a bad choice as it has the 4L80E electronic transmission. 1991 Yukon doesn't exist. But 1991-1992 pickups, 1500's, are good donor choices.

Reasons for other years not being good swaps:
1988-1990 have a different shape on the block where it attaches at the firewall, square instead of rectangle. Some hacking could solve that but there are other differences as well such as TPS connector being different and a few others.
1993-1994 have electronically controlled transmissions (4L60E) and the PCM to match, so the harness is quite a bit different.
1995 is a whole 'nother animal all to itself; lots of one-year-only differences.

Richard

BTW, fire at the rear there seems like possible fuel leak at the rear of the TBI? Have you identified the cause for the fire?

Richard

If the 92 is like my 96 the connector on the passenger side does not disconnect. You have to go in the cab and disconnect 2 plugs and then pull the whole thing out.

I'd be tempted to just throw a carb and a distributor on it.

someotherguy said:

The driver side on the other hand does indeed disconnect at the firewall, but it seems like it won't, because it is held in place by a thick black tarry goo which protects the connections from moisture intrusion. That is a whole separate harness section from the one on the passenger side so it may not matter in your case unless it is also significantly damaged.

Richard

Click to expand...

Richard's right about that disconnect at the drivers side firewall alright. Seems like it won't come apart.....till it does. Mine made a loud POP when it did come loose. I swore I must've broken something but I didn't. It just pops apart like that with that nasty black tarry adhesive/ sealer or whatever it is.

Silverado1994 said:

Richard's right about that disconnect at the drivers side firewall alright. Seems like it won't come apart.....till it does. Mine made a loud POP when it did come loose. I swore I must've broken something but I didn't. It just pops apart like that with that nasty black tarry adhesive/ sealer or whatever it is.

Click to expand...

Then you discover that it comes apart in 4 different sections once you reach in there with a pick to unlock the hidden tabs holding it all together.. whole 'nother revelation of GMT400 harness education.

Richard

Thank you guys for your feed back is really a predicated...
I went to the yard and found a decent clean tbi 350 harness for cheap 27bucks..with the pump relays.. The wiper mortor conector.. All the block conector... Map sensor..
.. The only issue is that is for a 4l60e tranny cause has more than 6 wires harness going down the firewall.. Towards the transmission... While... My tranny harness is for the 700r4.. Tranny.
So today I removed what I Coud of the melted shake of cables. From the firewall..
I was wondering if I can just keep the 700r4 wires coming from the tranny and connect them somewhere on the new harness fron the yard.. Maybe if there's the same. 6 color wires like in mine... And the rest of the harness I got.. to the rest of the sensors and block..?
Possible?

The parts house sells split wire loom to cover up the wires so it can look factory I would first wrap them with black electrical tape.
Good luck! GMC