CJ wiring harness

jeeperjoe

New member
i have a 76 cj with a slight electrical problem. i think there is a short somehwere. the wiring is somewhat of a mess. does anyone think it is pheasable to chaulk it up and redo the whole thing, or is that a nightmare and try to fix what i got??
 

If by you have the time and energy to re-wire the Jeep from scratch, using the old harness as a kind of template, It would probably be worth it. Bulk wire isn't that expensive, especially if you reuse some of the old stuff.

But If you're talking about buying a pre-made replacement harness, it is probably not worth it, since they are so expensive and probably have more wiring than you really need.

-Nick :!:
 
Joe,

If youre wiring is really really really bad and of course you love your truck maybe a new harness is the answer.

Oh sure you can make up your own new wiring harness but you wont be able to get the correct connectors and you'll be forced to clip off the old and reuse them and well the whole thing will look a mess.

I recommend you give $400.00 to PAINLESS WIRING
they have CJ5/CJ7/CJ6/CJ8 harnesses completely assembled with NEW connectors and a NEW fuse box using new style blade type fuses,

This harness is for the entire truck. under dash/lights/engine/trans, ect.

The harness is a simple yank out the old & pull in the new & plug in the connectors

TRUCKS TV show did it & it is one sweet system.

worth every dollar !!!
 
The painless harness is more convenient, but it is rediculously expensive for what it is.

I've just been re-wiring my CJ with inexpensive bulk wiring and using the stock fuse box. Seems to work fine so far.

The wiring schematics in the Haynes manuals are a little hard to follow at times. I wish i could get my hands on some of the actual Chrysler or original AMC service manuals.
 
sillsmack said:
Joe,
Oh sure you can make up your own new wiring harness but you wont be able to get the correct connectors


Actually, the GM OEM style connectors that Jeep uses in it's harnesses are for sale at NAPA autoparts. They are made by NAPA/Beldin and work great!

Then the only connectors you'd have to reuse are the ECU (if applicable) and fuse panel (if applicable)

-Nick :!:
 

well where do i start. im pretty sure there is a short since my negative ground smokes when i jump it. why do i jump it? because i only get half a dozen tries at starting it before its dead. the batt is 1000amp, and kinda new, so that should be ok. none of the front directionals work. the dash lights have a mind of their own. the clock doesnt work. the blower doesnt either. there is nothing for an auto choke, i have to splice. and the nimrod who had it before did all sorts of wierd stuff. it used to have a plow and an electric fuel pump(with a toggle on the dash...hehe). so all that wiring is still there.

basically, the wiring needs a lot of attention and i dont know where to start. i dont think $400 is that outragous and if its not a total nightmare to replace i would know what everything is and where everything goes.

i was actually looking at the painless harness and it doent look that complex. i would hope that it came with a diagram. i have the haynes manual so i can always look at that.

the more i look at it, the more i think i should just fix it, but to know that everything is perfect is worth a lot. rather than fixing this and finding something else in a couple months.. and so on and so on. the way i look at it, if the labor involved to fix it is the same as rewiring the jeep. $400.00 is a small price
 
::BUMP::

Um, question.

How difficult would it be, or just very time consuming....lets say, can wire but never done it.

And, what should the fusses be in a 76?

opps, buss?

or was it the same for a few years?
 

I have spent a couple hours here and there over the past month or so straightening out my wiring under the hood and dash. I bought some of that black corrugated tubing at home depot and have gone through and one by one, moved or replaced wires to go in it. It makes everything so much cleaner. Plus, with jeeps our age, you are bound to find some really nasty wires that were just waiting for a really cold wet day to screw you. Its really not that difficult if you only do a couple wires at a time so you don't get confused, and if you double check that everything you've messed with still works every once in a while. That way if something goes wrong, you don't have to backtrack too far. Use zip ties to hold the wires in place if you need an extra set of hands. Solder all of your connections and use shrink tubing so you know it will last.
 
Hi-Ya Laura and Joe,

I would like to attempt helping out with your wiring problems, but helping is difficult because I am confused. It might take several posts to get a handle on the problems.

I guess I need to have some questions answered.

Q-1: I asked early in this thread if this was the Jeep with a Chevy SB-350 engine that Joe recently purchased, but that question was never answered in the succeeding posts.

I asked that question because modifications to the original Jeep wiring harness would have been necessary when the SBC-350 was installed to replace the original engine. Unfortunately, that engine swap, in terms of wiring, is not a simple "plug and play" situation.

So....if you guys go with the "Painless" wiring harness solution, will "Painless" make up a custom harness for a 76, CJ with a Chevy SB-350 engine? If not, and only a stock 76 CJ replacement wiring harness is available, then you guys will have to modify that brand new Painless harness during the install to make it compatible with the SBC-350. Is that where you want to go?

Q2: The situation Joe mentioned with having to jump-start the CJ after six tries at starting and the smoking negative battery cable is obviously abnormal. Can you elaborate on that problem? When (during what conditions) does that happen?

Q3: Joe mentioned having a toggle switch on the dash to control an electric fuel pump. Is that switch still needed and functional? If not, then how is electrical power now being delivered to the electric fuel pump? (This is one of the electrical complications resulting from the SBC-350 install. Will Painless make up a harness that incorporates a key-on hot provision for the electric fuel pump?)

I have more questions, but the above are likely going to cause an overload, so I will stop here -- for now.

The dash lights, directionals, clock, blower motor problems are minor and better dealt with later.

Regards,

Gadget
 
Gadget!

I should let Joe answer, because you need a more technical answer..he knows and has been under there more then me....I can tell you it's the Jeep with the Chevy 350sb...
 

All the Tri-state Area GA, FL, AL

My advice would be to remove any of the wiring that was added and no longer needed.
Check for grounds on all the remaining circuits after all of the junk wire is out of the way.
Grounding is very important on a Jeep and some things may have been overlooked when the 350 was installed.
Most of your lighting/dash problems may be a bad/weak ground.
Your neg cable smoking when your jumping it is a pretty good sign that you've got bad grounds somewhere.
Get a book that has GM charging systems in it if you still have problems after checking everything.
I wouldn't sink the money into a new wiring harness until tracking down all the ends first.
Keep us posted on your progress. 8)
 
You guys need to see the mess under there. Joe wasn't exagerating when he said who ever did it was a nimrod. We were looking at it this past weekend, and it was like 2" of wire and a splice, then 2 more inches and another splice and so on, it is really messy. Overwhelming actually.

I'm gonna take pictures.
 
Painless makes two Cj harnesses. One with the terminals crimped on the ends and one without. The one without has a little extra length on the end so you can route it where you want and then crimp the terminal on there. They probably make a harness for that conversion also, but if not use the one that you crimp yourself. The motors should use the same wires just in different lengths. After all, if you are not fuel injected the majority of your wires are under the dash to the gauges and lights at all four corners.
Also the Painless comes with a piggyback blade type fuse panel. The wires are all labeled and you will be a lot better off than repairing someone else's mess.
 

sorry gadget,

i didnt realize that you were still wanted to help. my last set of problems is nothin. let me get you started.. i did pull out the existing radio, and wasnt completely sure that i got everything buttoned up so i went under the dash to check it out....and WHAM! the most horrific wiring job i have ever seen. splices everywhere, wires that went to nowhere, wires that went everywhere, wires that change color more than 4 times. and not to mention its got those fuses that look like teeth(lack of a better term) not bus fuses, the other ones. so naturally it has been rewired before. the guy who did it before must have owned electrical tape factory. that stuff is everywhere...everywhere. and all dried out.

#1 yes this is the jeep with the 350, but there are no electronics on the engine, other than the senders and the choke. you say the painless would need to be modidfied? it seems like it would be "plug and play". other than mounting it to the t150.

#2 the jumpstart thing. OK the jeep doesnt start. when i hook up the jumpers, everything looks fine, but after a few turn the battery ground, on the alternator bracket, starts to smoke.

and #3, the 350 has a mechanical feul pump. the electronic one is dead, except for the wiring

it comes down to i need to rewire the jeep. do you think it would be smarter to by the painless harness...all preterminated. or just go buy a boatload of bulk wire and heatshrink??

PS. i do appreciate your help
 
Hi-Ya Joe,

Give me a bit to look something up. My previous CJ, with SBC-350, had wiring mods to mate with the Jeep CJ wiring harness.

I need to look up why that was done.

Will reply soon.

Gadget
 
I had the same problem with my 63 cj5, not to the same extreams but the guy who did the wiring before i got it was a total idiot. Wires just dead ending into no where, groundings were no good, and just weird things i've never seen done before. So, i took it upon myself to tear all the wiring i seen out of that puppy and im looking to get me a brand new wiring harness. This way i can get a breaker and such, since im assuming mine didnt come with one stock . . . or the guy who did mine took it out for some reason. I havnt gotten the harness yet, but we'll see how she turns out.
 

hey jeepro, let me know if you are planning on using the painless harness.
 
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