1977 Jeep Cherokee Fire Rebuild

[ghcoe]

Time waits for no man, so hope you get to it soon

Me too. I was hoping to get it back and put back together before winter...

[ghcoe]

Time waits for no man, so hope you get to it soon

Me too. I was hoping to get it back and put back together before winter...

[ghcoe]

Jeep Fire Update:

[TSmith946]

I recently purchased a 1977 4door chief S that had a top engine fire 25 years ago. I have seen it run so I’m Following

[ghcoe]

I recently purchased a 1977 4door chief S that had a top engine fire 25 years ago. I have seen it run so I’m Following

Nice!
I had to rebuild the engine electrical loom a few years ago on this one. Had a dead short and fried the wiring back to the firewall. Was not too bad to rebuild the loom. I found wire with the correct colors to rebuild it. This time however, it is getting a painless wiring kit throughout.

[TSmith946]

I recently purchased a 1977 4door chief S that had a top engine fire 25 years ago. I have seen it run so I’m Following

Nice!
I had to rebuild the engine electrical loom a few years ago on this one. Had a dead short and fried the wiring back to the firewall. Was not too bad to rebuild the loom. I found wire with the correct colors to rebuild it. This time however, it is getting a painless wiring kit throughout.

What painless did you go with?

[ghcoe]

I recently purchased a 1977 4door chief S that had a top engine fire 25 years ago. I have seen it run so I’m Following

Nice!
I had to rebuild the engine electrical loom a few years ago on this one. Had a dead short and fried the wiring back to the firewall. Was not too bad to rebuild the loom. I found wire with the correct colors to rebuild it. This time however, it is getting a painless wiring kit throughout.

What painless did you go with?

P/N #10101 That is the one they recommended if you don't have electric windows and door locks.

[TSmith946]

I found a 78 wire harness at a junk yard. I left thinking I just stole the world. I get home and the bull head is perfect but the wiring was not.
So I plan to adapt it but the 78 diagram of the bull head on Tom Collins is illegible. I have tech manuals for 77/78 coming but is there anywhere else on line that I could find it? Not sure if I have the patience to wait… LOL

[tgreese]

This is a direct link to the diagram you can't read.
https://www.nmr.mgh.harvard.edu/~reese/ ... lkhead.png
Did you reach out to Stuka?

Looking at what I can read on the '78 diagram, the circuit numbers going into the bulkhead look almost identical. If you change to the (much better!!!) '78 components, and move any wire locations that have changed, it should match.

The '78 components are key. The circuits on the '78 harness do not match the '77 components. They just do not. You need to change the ignition and the alternator to what was supplied in '78. You could convert the '78 harness to the '77 alternator and regulator, but considering how you are struggling with this, that may not be realistic.

A Painless harness will be a lot more work, and it really really won't match the '77 electricals. Just FYI. Note that Painless is the most expensive "universal" hot rod harness on the market. There are a lot of competitors.

If this is beyond you, there are Jeep junkyards that may have a '77 FSJ you can pick an engine harness from. IIRC Z&M Jeeps offers some new replacement harnesses, but maybe not for the execrable Prestolite stuff.

[ghcoe]

A Painless harness will be a lot more work, and it really really won't match the '77 electricals. Just FYI. Note that Painless is the most expensive "universal" hot rod harness on the market.

The painless uses the GM color codes of that era. For the price ($284 at this time) I don't really think you can go wrong.

I rebuilt the engine harness completely a few years back. It was $100.00 for the color correct GXL wire and wiring pins that went into the fire wall pass through plug. GXL wire is a better wire than common primary wire and/or the original OEM wire used in these Jeeps.

Painless uses GXL wire and supplies the extra connectors you would need in a GM vehicle. Luckily Jeep used a lot of GM products so most should work. With the addition of a ATO fuse style fuse box (in my case) I think it would be very hard to find a comparable vendor at a lower cost. If you're building a show vehicle then you might consider replacing the wiring to factory, but for a driver I feel it would be better to upgrade to the newer wire standard and upgrade the fuse box at the same time.

Now if painless made a factory wiring harness for the SJ platform, I would jump all over that, but till someone does you have to do what you have to do. With the painless you can upgrade to other types of charging systems. You can go stock or change over to a wide variety of high output options. Same with the ignitions. Read through the Manuel https://www.painlessperformance.com/Manuals/90501.pdf .

[tgreese]

I think the main issue here is compatibility with the Prestolite ignition used in '77. If enough of the old harness is intact, possible the poster TSmith946 could splice the connectors to a hot rod harness and keep the Prestolite stuff. Considering he has an intact '78 harness meant for the far less problematic Motorcraft ignition, that seems like the clear best path forward. His '78 harness should plug in to a Motorfract distributor and module.

I agree that buying enough different colors of wire to duplicate a factory harness would be prohibitively expensive. A hot rod harness provides a lot of wire at a reasonable price. Harnesses can be had for as little as $30 on eBay, though I expect the wire quality is not comparable to a name brand like Painless.

You could also take wire from a junkyard harness, if the yard will sell the harness for a reasonable price. Then build up the replacement OEM-style harness using the wire and connector shells from the old harness.

I would also point out - this is a thread hijack. The poster TSmith946 asked this question in his own thread here viewtopic.php?p=225760#p225760 Up to the mods if they want to split it off.

[ghcoe]

New update...

[devildog80]

Labor of love, and glad your taking it on, to save another perfect Jeep from the scrap heap!

[ghcoe]

Labor of love, and glad your taking it on, to save another perfect Jeep from the scrap heap!

Thanks!

[ghcoe]

Rather than rewrite all the rear fare replacement info here I am just adding this link to that viewtopic.php?t=24155 .