Which harness and PN for my situation please?

jmarkel

Scrambled for Life
City
Fairfax Station
State
VA
#1
I"m getting close to start the wiring portion of the 4 year long project and it's now time to purchase the harness. I assume I want the painless harness but there are variations and I want to get a recommendation. Equipment on the jeep is the original 258 with a 4.0L head and a Throttle Body injection system. I'm going to be putting a GM style distributor on it. It will also have an AC upgrade to it from Jeep Air.

I want this to be as easy as possible...I'm good with this sort of activity, but I absolutely hate doing it, so pre terminated is going to be preferred.

Thanks for any input.

THanks
 

walkerhoundvm

Just trying to stay upright
LIFETIME
CJ-8.com Member
City
Cave Creek
State
AZ
#2
I've always assumed that painless was the way to go, but my shop bitched about it incessantly. I've read of other people having problems with it and recommending products that were half the price (ez comes to mind). Preterminated probably saves you double the cost in terms of your time, though, based on the limited harness work I have done.

Not having any direct experience with a full install, I don't really have an opinion, but the shop made it sound like painless was the end of the world.
 

barrys

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
East Norriton
State
PA
#3
You can check out centech. Much smaller company and could possibly customize a harness to a certain degree. Not sure bu t worth looking into.
 

John N

Addicted....Ex-SOA VP
LIFETIME
CJ-8.com Member
SOA Member
City
Rockville
State
VA
#4
Ron Francis Co. makes excellent wiring harness products also.
 

tower210

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Olathe
State
KS
#5
You can check out centech. Much smaller company and could possibly customize a harness to a certain degree. Not sure bu t worth looking into.
You might search the forum here on this one.... Pretty sure someone else had the same question recently and went Centech... Not sure if they have installed yet...
 

jmarkel

Scrambled for Life
City
Fairfax Station
State
VA
#6
I found a guy that has the same setup as me using a Painless, but he hasn't come back with the part number he used. I looked at Ron Francis but didn't find one suitable. I'll look at the Centech ones next and i'll probably call Painless and see if they can recommend for my setup. I'll report back when I have info.
 

jmarkel

Scrambled for Life
City
Fairfax Station
State
VA
#7
I spoke with Painless today. The tech told me I wanted part number 10150 for jeep CJ series. Some sites say that the harness will not work with CJ8 and that's because the length of wires going to the rear need to be extended in some cases. Other than that, it should be ok. That's currently available for $829. The Centech also has preterminated and plug and play stuff going on with it. Same issues on length of wires to the back. Other than that, I don't see it having any downside that I can tell. It should be fine as well at $550.

I searched forums for people's accounts and haven't seen too many that show the whole process end-to-end or a real review one way or the other. But based on what I see so far, I think I'll probably go with the Centech unless someone thinks I'm making a big mistake by doing so.
 

barrys

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
East Norriton
State
PA
#8
Did you can Centech about possible customization? They used to be a small company based in my friend's neighbors garage. Often easier to get custom stuff from smaller companies.
 

tower210

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Olathe
State
KS
#9
I spoke with Painless today. The tech told me I wanted part number 10150 for jeep CJ series. Some sites say that the harness will not work with CJ8 and that's because the length of wires going to the rear need to be extended in some cases. Other than that, it should be ok. That's currently available for $829. The Centech also has preterminated and plug and play stuff going on with it. Same issues on length of wires to the back. Other than that, I don't see it having any downside that I can tell. It should be fine as well at $
I did the painless on mine about 6 years back. Single best upgrade in reliable I’ve done. It’s a lot of work...but that’s the nature of the beast. Painless regularly sponsors Jeep outings and you can win pretty good coupons...
 

jmarkel

Scrambled for Life
City
Fairfax Station
State
VA
#10
I talked to Centech today and after considering everything, decided on them and make the purchase. I talked to a guy that knew a lot about jeeps and the scrambler in particular and asked me a few things about my setup. He was going to lengthen the lines for me so that it would be plug and play to the back. I also mentioned I"m putting a GM HEI so he said that he'd make sure that was setup correctly with the right terminal ends as well. I also mentioned that I had a Howell Tbi and he said that they would be sure to label the lines that would connect that in so there would be no guess work. Add in the fact that everything comes pre-terminated and has all new bulbs, it seemed like a good deal.
 

barrys

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
East Norriton
State
PA
#11
Hopefully their harness will be as good as it sounds. I knew they moved from their original location, didn't realize they were still only 30 minutes from me(just checked). If I need a new harness someday, I hope I can just drive up and chat with them. Please let us know how it works out.
 

jmarkel

Scrambled for Life
City
Fairfax Station
State
VA
#12
The idea of putting a complete harness in wasn't something I had seriously considered. There were no issues with the existing wiring of the jeep before the teardown. It was never hacked up. When I got the jeep, and installed the Howell TBI and the MSD ignition I was very careful not to make a mess of things. However, seeing I just invested a ton of money to build the jeep to basically new condition, I didn't want to cheapen out on the final steps and chose to do a new harness. I'm really only concerned about the integration of the Howell TBI to be honest. Everything else should be straight forward, but a slog. And I need a better location for the ECU than on top of the heater box...I want my glove compartment back.
 

John N

Addicted....Ex-SOA VP
LIFETIME
CJ-8.com Member
SOA Member
City
Rockville
State
VA
#13
My Howell ECU has been on top of the heater box for years, no issues...yet.
 
City
Halifax
State
UK
#14
I extended all the cables on my Howells harness and strapped it to the side of my seat base to make life easier on installing and also so i can get to it should the need arise.
 

jmarkel

Scrambled for Life
City
Fairfax Station
State
VA
#15
Mine was on top of the heater box for 10 years without any issue. I was doing tuning and some chip burning and had it there for ease of access. However, I suspect I'm dialed in the way I need it to be and am going to try and locate it somewhere else if possible. I wonder if there's room to mount it to the firewall on the outside near the steering column or on the passenger side fender where the jack goes? Maybe to the underside of the battery box?
 

walkerhoundvm

Just trying to stay upright
LIFETIME
CJ-8.com Member
City
Cave Creek
State
AZ
#16
Mine was on top of the heater box for 10 years without any issue. I was doing tuning and some chip burning and had it there for ease of access. However, I suspect I'm dialed in the way I need it to be and am going to try and locate it somewhere else if possible. I wonder if there's room to mount it to the firewall on the outside near the steering column or on the passenger side fender where the jack goes? Maybe to the underside of the battery box?
Consider those of us with 5.3 swaps and our pcm in the engine bay. I never considered it, but I had to check my pcm after a drive and it was almost too hot to hold.
 

jmarkel

Scrambled for Life
City
Fairfax Station
State
VA
#19
Now that I have the new Centech harness in hand and laid it out and such, I'm finding that I made a good choice. The harness is laid out well, as is the fuse box and connectors. Everything is marked clearly right on the wire as to where it goes. Haven't had any issues looking at it and getting it positioned for hookup. Just a few things I'll note for you.
1. The rear section is using really nice watertight connectors. That means that you will need to change the connectors that are on your original tail lights. It's an upgrade for sure. Not a big deal.
2. There seems to be plenty of extra length on the wires in the engine compartment. That's not a big deal, you'll just trim them down. They ran the wires all to the end and some need to be poking out of the sheathing midway so they get to the temp sensor and oil sensor easier. Just cut open a little tape and slide the wire up around the plastic sheathing, and retape. No issue.
3. The only critique I have is the through-firewall connector. It does not match the square that is original to the firewall, it is round. They supply a stainless cover that you can screw into the firewall and then screw this connector through it...but it's flimsy. I ended up making my own out of a 4x4 piece of 1/8" thick steel that I blasted and coated with POR15. I drilled the 4 corners and matched 4 holes to center it on the square and used a 2" holesaw for the through hole for the connector. I put some silicon on and let it setup and then I bolted it through. I didn't want to use screws here as I felt I wanted it to be water tight and solid...overkill maybe, but it will never be an issue based on what I did.
4. Lastly, some of the runs of wire are unsheathed longer than I'd like. For example the horn lead or the washer lead, the underhood lead. I have some single line tough nylon wire sheathing I'll be putting on top of these. Probably overkill but it will look better and offer some protection of those wires.
5. There are two blank slots on the fusebox so I can wire things up that I need. I'll be using one for the radio and some Aux lighting, and the other one will be for the AC. There are also a few open slots that you can add hots from existing fuses...maybe run the radio from one of those instead of its own? My jeep will remain fairly basic and doesn't need more fuses, but Centech also sells aux fuse blocks too, which would be a pretty easy answer if I wanted more accessories in the future.
6. Extra grounds...there are extra grounds everywhere. I feel that there are so many extra grounds to attach to chassis and there are supplied stainess screws to anchor them. I'll be using all of them just to make sure ground is never a problem.

As stated before, they did add in the length needed so that it reaches to the back on the Scrambler, and added in the correct connectors for the HEI ignition and Tach. They also supplied all new bulbs for the dash (not the rectangular ones, just the normal bulbs). The also furnished a set of other connectors...i may or may not need those.

I plan on finishing all the wiring this week, and am not expecting any issues.
 

TXJEEP

Legacy Registered User
City
Copper Canyon
State
TX
#20
A lot of people here know a lot more about this than me but in my research the length of wiring for the CJ-7 and the CJ-8 are the same due to a difference in how they are routed. I only bring that up because I do not think you need to be concerned. I ended up purchasing the Painless product with the Trail Rocker (all really expensive) and everything is working out well. I am only about 25% into it so far and have not addressed the EFI. I will share my thoughts after I finish it in a couple of months. :-)
 
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