Just got my 1982 J10 home….. questions…

[Swbtwo]

Looks like some PO installed an exhaust system welded together end to end and crossing under the oil pan in such a way as to make removal impossible without removing the crossover pipe. Of course one of the bolts in the flange to the pipe/manifold connection can’t be reached because of the driver’s side engine mount. Such fun. I’m thinking about cutting the pipe where I can use a temporary connection to rejoin it until I have it all replaced.

[Yeller]

Don’t be afraid of using stainless band clamps. They are by no means a temporary fix, marine and racing have been using them for decades successfully. I hand build a lot of exhaust and put these in strategically so it can be removed or installed, I have yet to have a failure. Semi truck industry uses them to install everything.

https://www.amazon.com/SPEEDWOW-Joint- ... 277&sr=8-5

[Swbtwo]

Don’t be afraid of using stainless band clamps. They are by no means a temporary fix, marine and racing have been using them for decades successfully. I hand build a lot of exhaust and put these in strategically so it can be removed or installed, I have yet to have a failure. Semi truck industry uses them to install everything.

https://www.amazon.com/SPEEDWOW-Joint- ... 277&sr=8-5

Thanks, I’ll do it.

[Swbtwo]

Finished replacing the rear main seal. It was stuck and really difficult to removed, so I loosened all the main caps and was able to remove it. It had to be the factory seal. The oil smelled burnt and there was a grit film. I have a feeling I’m not done with the bottom end on this thing, given this rear main bearing.

[tgreese]

Ya know, I would not condemn the bearings on appearance alone.

When running, there is no actual metal-to-metal contact. The oil pressure maintains a film of oil that separates the bearing from the journal. If you have good oil pressure and no banging or thumping noises, I'd say it's not at EOL yet.

Mains contact typically has a low-pitch thumping noise, lower than the bang-bang you hear when a rod fails. Just FYI.

[Swbtwo]

Finished up on the gasket replacement and oil change of the differentials and the engine RMS, oil pan gasket. Decided to take the truck around the block for its first road test. The results weren’t good. It ran rough the entire way and when I returned to the driveway I had smoke coming out from under the hood. Looks like more of the wiring harness decided to melt.




Worse (?) I was greeted by an oil puddle where the truck had run before I set off. Looks like the RMS is leaking like a sieve.

Ugh.

Next step, anyone?

[will e]

The melted wire normally provides power to the coil while cranking the engine. The normal wire is a 'resistor' wire and while you are cranking the engine the volts drop pretty significantly. The solenoid connection side is closed during cranking. When the engine is in the normal running position this wire will have power from the coil back to the solenoid but the circuit is incomplete. It most likely grounded on something and that cause the melting. It would also be one explanation for the engine running poorly.

carefully disconnect it form the coil and then check to see if it is grounding out.

[Swbtwo]

The melted wire normally provides power to the coil while cranking the engine. The normal wire is a 'resistor' wire and while you are cranking the engine the volts drop pretty significantly. The solenoid connection side is closed during cranking. When the engine is in the normal running position this wire will have power from the coil back to the solenoid but the circuit is incomplete. It most likely grounded on something and that cause the melting. It would also be one explanation for the engine running poorly.

carefully disconnect it form the coil and then check to see if it is grounding out.

Is it possible the fault is in the ignition switch itself?

[Swbtwo]

I pulled the engine wiring harness and it’s not pretty. This first picture shows an end that was folded over and wrapped with electrical tape.

[Swbtwo]

These are a few shots of other parts of the harness where duct tape was used.

[Swbtwo]

End to end. If anyone needs a close up for diagnostic purposes let me know.

[Swbtwo]

I think repairing this is beyond me. I’m wondering if there’s someone that repairs these, and if so, if I’m having this repaired anyway, is now the time to have it modified to run a fuel injection system?

[tgreese]

Mmm. What's putting you off about the electrical? You need to locate the source of the short. Red is the start wire, and should only be connected when the ignition switch is to start. I would try to locate the issue before the harness was removed.

Finding a shop that will work on an old car like this may be difficult. Old cars are a rich man's hobby if you have to pay someone else to work on them. Once you find a shop, it will likely be expensive, especially if you expect them to sort out existing problems. Maybe check with your local 4x4/Jeep clubs or bulletin boards.

[Swbtwo]

Mmm. What's putting you off about the electrical? You need to locate the source of the short. Red is the start wire, and should only be connected when the ignition switch is to start. I would try to locate the issue before the harness was removed.

Finding a shop that will work on an old car like this may be difficult. Old cars are a rich man's hobby if you have to pay someone else to work on them. Once you find a shop, it will likely be expensive, especially if you expect them to sort out existing problems. Maybe check with your local 4x4/Jeep clubs or bulletin boards.

To be honest, I wouldn’t know where to begin with all that burnt and fused together wiring (not to mention the duct tape splices) as to the cause. That’s why I asked if it’s possible that this is related to the ignition switch since the first wire melted as the lock on the ignition seemed to be stuck between positions. Electrical is the weakest part of my wrenching skills so I’m at a loss. I was hoping someone would tell me there’s a vendor who rebuilt these.

Failing that I’ll try to find one on eBay/Craigslist that isn’t as much of a basket case. That said, if everyone’s advice here is that I should repair it myself, I’ll give it a shot. I pulled it to see how bad the damage is throughout it and whether or I not I felt comfortable tackling it. At a minimum I’d have to cut/splice the wires that fused together as they melted, before I could trouble shoot it, right? Again, lost here.

I wasn’t really thinking, at least at this point, that I’d have to dump the truck on a garage to sort out.

[tgreese]

The duct tape is probably factory equipment.

I'd suggest you get a big piece of paper and colored pencils and trace it out. Just requires a clear head and patience. A short to ground would cause burnt wires. Get a multimeter and measure the suspect connections.

[Swbtwo]

The duct tape is probably factory equipment.

I'd suggest you get a big piece of paper and colored pencils and trace it out. Just requires a clear head and patience. A short to ground would cause burnt wires. Get a multimeter and measure the suspect connections.

Duct tape from the factory? It’s amazing the things I learn here.

Thanks for the advice, I’m going to do this.

Still worried about the RMS kicking out so much oil. I hope I didn’t damage anything pulling out the old one…

[tgreese]

I have the printed paper '82 TSM that I bought from BJ's. It came with the wiring diagrams on folded 11"x17" paper, as an insert to the manual. There is a separate page for the 6-cyl Cherokee-Wagoneer-Truck feedback system. Not trying to spend your money... However, this would help you identify what you have. The six-pin connector is the diagnostics plug.

I think BJ's sells the Bishko reprints? It's not marked as such - maybe they would tell you. RockAuto offers DetroitIron brand reprints - I don't know how the quality compares. You could also buy a printed copy from Faxon in Riverside CA, and you should get the best quality reprint available.

I've told this a lot on here, but it bears repeating. When I was a teenager, I would go to the local library and photocopy wiring diagrams from the year car I was working on. I'd then use their copy machine to blow the diagrams up, piece by piece, to double size from the book. I would tape the pages together so the wires lined up, and trace out the circuits with color pencils. You can buy a pack of maybe two dozen colored pencils at the art supply store. This would both get the specifics into my memory, and provide an unambiguous reference for the harness. Just a suggestion of how to start.

[Swbtwo]

I have the printed paper '82 TSM that I bought from BJ's. It came with the wiring diagrams on folded 11"x17" paper, as an insert to the manual. There is a separate page for the 6-cyl Cherokee-Wagoneer-Truck feedback system. Not trying to spend your money... However, this would help you identify what you have. The six-pin connector is the diagnostics plug.

I think BJ's sells the Bishko reprints? It's not marked as such - maybe they would tell you. RockAuto offers DetroitIron brand reprints - I don't know how the quality compares. You could also buy a printed copy from Faxon in Riverside CA, and you should get the best quality reprint available.

I've told this a lot on here, but it bears repeating. When I was a teenager, I would go to the local library and photocopy wiring diagrams from the year car I was working on. I'd then use their copy machine to blow the diagrams up, piece by piece, to double size from the book. I would tape the pages together so the wires lined up, and trace out the circuits with color pencils. You can buy a pack of maybe two dozen colored pencils at the art supply store. This would both get the specifics into my memory, and provide an unambiguous reference for the harness. Just a suggestion of how to start.

I really appreciate the help. I have a reprint of the TSM but not the version with the with the folded wiring diagrams. I have a lower quality version where the diagrams are pretty much impossible to read. I just ordered the BJ version to remedy that problem. I’m also taking your advice about drawing out the harness. Then I’ll take care of the burned wiring, make sure it works, then tape it up. I’m also restoring a mid-60s Datsun roadster with a bad harness so I’m learning a skill that will save me considerable money on that project. A virtuous cycle.

It looks like the most recent prior owner put a brand new Carter BBD carburetor back on the engine and plugged the wiring harness into it even though an owner before him had removed the MCU and taped all the connections at that end of the harness into a ball. I’d like to replace the carburetor (probably with the Weber since the Gronk guy no longer seems to be around) and the distributor (HEI?) to simplify the wiring and vacuum systems.

[tgreese]

Glad I could help. If you go with the Redline kit, I'd point out that the population size of FSJs with the 258 and stepper-motor BBD is small compared to the number of CJs that were sold with this combo. If you have issues, you might broaden your search to include that community. I recall the site owner Stuka has or had a J10 with the 258 and Redline conversion.

If it were for me, I would skip the carburetor replacement and go direct to fuel injection. (I would convert my Jeeps but there are too many demands on my time currently. No time for car projects and too many cars.) There are several conversion kits for this application, including Holley Sniper and Howell. The Sniper seems well liked, and seems to be as close as you can get to a true bolt-on conversion. Most of the others use the GM Rochester TBI (throttle body injection) parts adapted to the specific engine.

There are also vendors like Bill Hamilton that will tailor a system to your engine using the GM parts. This can include advanced features like spark control and a knock sensor that will be missing on an "electronic carburetor" like Holley or Howell. The advantage of the GM parts is easy sourcing and replacement in the field, compared to a custom system like the Holley Sniper.

If you have the original distributor, I would point out that the only difference between it (the Duraspark) and the GM HEI is packaging. Same operating principle, same capability, one is Ford and the other is Chevy. You can mix and match components between them. One popular change is "Stealth HEI" where you hollow out the Duraspark module and install the HEI module inside the empty case. Completely compatible.

[letank]

a bit late... but usually one wire shorts and take the other near by wires with it... Yes, duct tape is OEM, usually by the resistor wire for the coil but you can figure it out by the color, may be the ammeter wire, if you still have the ammeter, time to do the bypass.

I had to do the same things a few months ago... I removed the electrical tape and separated the melted wires.... then did a replacement for a bit longer than the damaged length... stagger the connectors so the loom can be put back on or buy a wider loom