1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Painless 10150 For 1975 Cj5

Discussion in 'Intermediate CJ-5/6/7/8' started by 75CJ512JK, Dec 4, 2019.

  1. Dec 4, 2019
    75CJ512JK

    75CJ512JK New Member 2020 Sponsor

    Tucson AZ
    Joined:
    Mar 15, 2017
    Messages:
    14
    It is my understanding that the 75 wiring is similar to the 76+ wiring aside from a few 75 specific items. (ie Spartan Turn signal, ignition on dash)

    The Painless 10150 is the new version of the 10110. Called Painless and the Engineer that designed that specific harness said with some slight modification ("rerouting dash wiring") it should be a the closest to a direct fit.

    I have read many threads on different forums but I am still a little unclear as to what exactly won't be plug and play between the 10150 (10110) and the 75 CJ5.

    Edit: This thread contains a few users that chose the 10110 on their 75's:

    wiring harness 75 cj5 choices


    Any wisdom would be appreciated.
     
    Last edited: Dec 4, 2019
  2. Dec 4, 2019
    timgr

    timgr We stand on the shoulders of giants. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,828
    Do you have the '75 TSM? The wiring diagram for the CJ is in there. Compare that to the Painless diagram.

    No "hot rod harness" like the Painless product will be plug-and-play. It comes with a fuse panel with a bunch of un-terminated wires. You are expected to install the panel, route the wires, and terminate the wires at the devices you have, like the lights, switches and so forth.

    The factory wiring harness is custom-made to be the right length and has the right terminations to plug-in to the vehicle. All this stuff is designed to be assembled by the factory crew quickly. This is "plug-and-play," but extensive design and testing went into making these harnesses. The hot-rod harnesses are nothing like that.

    A '75 is the first year for the through-the-firewall bulkhead connector that is integrated with the fuse panel. When you remove that, there will be a big hole in the firewall that you'll need to fill with ... something. The hot rod harness comes with a fuse panel meant to mount flat somewhere on the hot rod, typically under the dash. It's then up to you to route the wires through the firewall and to the rest of the Jeep.

    What do you have now for wiring?
     
    Rubicloak likes this.
  3. Dec 5, 2019
    75CJ512JK

    75CJ512JK New Member 2020 Sponsor

    Tucson AZ
    Joined:
    Mar 15, 2017
    Messages:
    14
    Right now its stock.

    Going to start a frame-off with some modernization mixed in. HEI, EFI, etc.

    I'm okay welding a cover over the hole for the old bulkhead. That doesnt sound like anything too difficult.

    So if I'm understanding correctly, I'll need to fashion another way for the front/engine bay wiring section to get through the firewall from the fuse box that will be located on the inside...
     
  4. Dec 5, 2019
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2021 Sponsor 2020 Sponsor

    cordele, Ga.
    Joined:
    Mar 29, 2007
    Messages:
    5,758
    Yes you will. Like the early jeeps used a rubber type grommet for the wires so it will be protected from chaffing.
     
  5. Dec 5, 2019
    timgr

    timgr We stand on the shoulders of giants. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,828
    What's wrong with the factory wiring? I'd add an auxiliary panel to power your modernization, rather than rip out the factory wiring. Why reinvent the wheel?
     
    dane71 likes this.
  6. Dec 6, 2019
    75CJ512JK

    75CJ512JK New Member 2020 Sponsor

    Tucson AZ
    Joined:
    Mar 15, 2017
    Messages:
    14
    Well the wheel was re-invented many times over as technology, material, and processes got better. So my thought was 45 year old wiring, wire insulator, connectors, etc. might be worth replacing with something new while the frame-off was happening.
     
  7. Dec 6, 2019
    timgr

    timgr We stand on the shoulders of giants. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,828
    I'm sure you understand what I was trying to suggest by using a popular expression. By all means, make the wiring anew if you have the time, means and it's important to you.

    IMO it's more an aesthetic choice than a practical one, unless there was a fire or wreck or such. I have had - at most - only minor problems with factory wiring on my '75, '77, and '82 Jeeps. The wiring does not seem to me to deteriorate as much as you might imagine. The insulation is vinyl and does not seem to age much where it's protected from UV. I have no trouble understanding the factory wiring diagrams, and it seems to me that the factory documentation is both more specific and more detailed than what you might get with an aftermarket harness.

    This thread discusses maintenance and repair of factory harnesses extensively - https://www.jeepforum.com/forum/f8/basic-wiring-101-getting-you-started-1340134/ - not unreasonable to spiff up a few bits here and there using some new parts.
     
  8. Dec 6, 2019
    sterlclan

    sterlclan Member 2021 Sponsor

    exploring the...
    Joined:
    Feb 21, 2009
    Messages:
    3,646
    Fwiw the hole in the firewall is the same as a square body Chevy truck. Most of the things you sound like you are doing would be easily accomplished with a harness from an 87 this would have the ecm harness for your efi as well.
     
  9. Dec 6, 2019
    75CJ512JK

    75CJ512JK New Member 2020 Sponsor

    Tucson AZ
    Joined:
    Mar 15, 2017
    Messages:
    14
    I do understand and I wasn't trying to sound like a smarta--. The Jeep was stored outside in New Mexico all its life and the wires look decent, but when the project is finished I want to know that ever inch was checked and if possible improved in one way or another.
    Sentimental maybe, a labor of love for my old high school jeep, and maybe this is one of the times I'll look back and say, "Damn, I wish I would have listened to the wisdom from the Jeep elders." At this point I might stick with stock and keep the Painless kit in the personal inventory.

    Either way,
    I was looking through the kit (Black Friday special on Painless) and the Painless fuse block/bulkhead looks like a direct fit (minus bolt size) for the stock 75 firewall. Pics Attached. Am I missing something here? It looks like no modification would be necessary. Jeep Bulkhead.jpg Painless.jpg

    Again, thanks for the wisdom.
     
  10. Dec 7, 2019
    sterlclan

    sterlclan Member 2021 Sponsor

    exploring the...
    Joined:
    Feb 21, 2009
    Messages:
    3,646
    yup looks like your standard gm style plug, if you have the painless kit already use it the wiring on these isn't terribly complicated.
     
  11. Dec 9, 2019
    Raven74CJ5

    Raven74CJ5 New Member

    san diego,...
    Joined:
    Jun 13, 2018
    Messages:
    24
    Just got done not to long ago installing a painless kit on my 74... took 2 days to completely removed and rewire the whole thing... and im glad I did. As I was going through the old wiring I found a lot of placed where the wires were cracked and oxidation set in causing the wires to corrode. I too upgrade with a few modern perks on my jeep by adding a high amp single wire alternator and an HEI distributor. IMO its definitely worth the time and effort to upgrade to new wiring especially with the newer modern upgrades in electronics these days.
     
    Lockman and 75CJ512JK like this.
  12. Dec 9, 2019
    timgr

    timgr We stand on the shoulders of giants. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,828
    Actually kind of cool that the bulkhead connector is a standard thing. Likely another instance of AMC/Jeep taking existing big-three parts and adapting them to their purposes. Using the GM-style bulkhead connector, they bypass all the R&D needed to develop the connector for their vehicle, and they only have to change the wire colors and lengths. I wonder how common the fuse layout in the panel is to other vehicles?
     
    Lockman and 75CJ512JK like this.
  13. Dec 9, 2019
    sterlclan

    sterlclan Member 2021 Sponsor

    exploring the...
    Joined:
    Feb 21, 2009
    Messages:
    3,646
    I would bet pretty similar I’ve used older harness with late model and vice versa to add injection to a pre 87 Chevy square nose. you just add the wire for the pump to the engine side of the bulkhead and add the engine harness for the ecm all plug and play.
     
    Last edited: Dec 9, 2019
    Lockman and 75CJ512JK like this.
  14. Feb 3, 2021
    Allan

    Allan 74 Renegade

    Olympia
    Joined:
    Jan 21, 2019
    Messages:
    244
    I have a dilemma, not sure what route to go on my 74 rewire.
    I know I could buy a brand new old stock 76 under dash harness but then where would I get harness for firewall to engine, front lights, rear lights, ect.

    I would have to cut a square hole weather I go with the painless or not because I want to go modern on the fuse block ect, also need a template to cut square hole in firewall, not sure where to find one, I want it to look professional.

    Or do I buy the 76 painless complete kit?
    What is the best route? Opinions?
     
  15. Feb 4, 2021
    bigbendhiker

    bigbendhiker Member 2021 Sponsor 2020 Sponsor

    U.S.
    Joined:
    May 26, 2019
    Messages:
    321
    Painless has several options for a 1974 Jeep CJ. If you have and are retaining the key in the dash, this should work.

    Painless Wiring

    And it only needs a 1.25" round hole through the firewall. If you click on the link above there's another link to a very detailed manual. There are several bundles of wires each designed and labeled to power the various areas you mentioned, engine, front lights, rear lights, etc.
     
  16. Feb 4, 2021
    timgr

    timgr We stand on the shoulders of giants. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,828
    The main issue I see with the '76 harness is the steering column. 1976 was the first year for the GM column, and you may have a lot to do to straighten out the difference with the bus column and Sparton switch. Realize that the indicators, brake lights, and hazards all go through the column and turn signal switch, so the column matters more to the overall wiring design than you might expect.

    If I were restoring this Jeep - even if I were building it for everyday use - I would just put the wiring back to stock. Walck's may have a replacement harness, if you don't want to repair or duplicate the original harness yourself. 1975 was the first year for the fuse panel in a CJ, and it is the only year with both the fuse panel and the bus column with Sparton switch. A '74 is the same electrically as a '73 and very close to a '72. The '72 TSM has helpful line drawings that show all the wire bundles and wire routing, making it easy to duplicate the original harness.

    I kinda feel like the '73-74 harness was fine for these Jeeps, and the fuse panel was added because customers (and maybe the designers/engineers) perceived it as more modern and an improvement. I'd also speculate that the GM-style bulkhead connection was easier and faster to assemble on the line, eliminating the step where the one-big-harness had to be threaded through the firewall. In general, all the plastic plug-in connectors in the wiring harness are there to make assembly easier, not because they serve any purpose on the assembled car. Indeed, any connectors become a potent liability once the vehicle starts to age (ie beyond warranty and factory support).

    JMO - this is a case where perfection is the enemy of the good. The '73-74 harness is fine for all the features of the original Jeep, and if you want to add accessories, it's easy to install an additional small waterproof fuse panel to power these. The original harness has fuses, though they are distributed as inline fuses in strategic places in the harness. Again, a CJ is so simple and basic that accessing and replacing these inline fuses is quite easy. Using the factory wiring harness avoids the need to document all the changes that were made to adapt the hot rod harness. This will be important if there are any electrical problems in the future.

    Also JMO - wire routing and protecting the wires is much more important to safe and reliable operation than having a lot of additional fuses. With the original harness, this has all been worked out for you by the factory.
     
    Last edited: Feb 4, 2021
  17. Feb 4, 2021
    timgr

    timgr We stand on the shoulders of giants. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,828
    I'd also comment - the company name "Painless" is brilliant marketing and framing. Not only does it tout the quality of the product, it frames the misery you will go through without their product. Realize that they are brainwashing you to fear this work. Automotive wiring is not painful - it's easy. One wire at a time, one circuit at a time. It's only painful if you try to take in the entire harness at once and are overwhelmed.
     
    Lockman likes this.
  18. Feb 4, 2021
    SFaulken

    SFaulken Member 2021 Sponsor 2020 Sponsor

    Marysville, WA
    Joined:
    May 24, 2011
    Messages:
    935
    Painless makes a nice product, but you're overpaying for a name, honestly. I've done a number of aftermarket wiring harnesses over the years, and my go-to are Speedway's generic 12-circuit house brand harnesses, and just doing my own termination with either Deutsch or Weatherpack connectors. To me anyway, it's just as simple as installing a Painless harness, and a hell of alot cheaper. Could I build my own harnesses? Sure, but it's not worth my time, when I can buy theirs for less than $200, and even cheaper than that, when they go on sale. I've actually got a couple extras sitting on the shelf in my storage right now, just because I had the extra cash last time they were on sale, and I knew I'd use them.
     
  19. Feb 4, 2021
    timgr

    timgr We stand on the shoulders of giants. 2021 Sponsor 2020 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    22,828
    One advantage of these hot rod harnesses that I do not dispute - they give you lots of wire in many different colors. It's difficult to buy enough colors to build one of these harnesses without running into a major expense. Quality of wire will affect the price of the harness - realize that you can buy a complete harness from China on eBay for about $35.
    12-14 Circuit Universal Wiring Harness Muscle Car Hot Rod Street Wires New | eBay
    This seems like a pretty good deal, if you were on a tight budget. Worth it for just the wire.

    Also suggest that you watch for primary wire cheap/on-sale ... I bought about a dozen Dorman packs of wire in various gauges and colors from RockAuto on close out a few years ago.
     
    Lockman, Fireball and SFaulken like this.

Share This Page

New Posts