Aftermarket/OEM engine wiring harnesses?

Any good sources that you guys have used other than the dealer?

Cory

For what?

I've built more than a few harnesses, but most problems you'll see (that aren't caused by a full burnout) are likely going to be a connector fault, which can be easily replaced. There isn't a lot to go wrong otherwise, as long as you don't keep things underwater and do keep them clean.

I've just gone through this with someone else - most of the connectors (the block bodies with towers and sockets) are Delco "Weatherpack" style connectors, which can be gotten from any local with a HELP! section - you'll find them under "ConducTite." I use them for a lot of my own mods, and I think they're quite good. If you can't find them locally, try Summit, Jeg's, or MSD - I know they all have them.

The oddball is the NSS connector - it's an 8-pole Desutch. Those can still be had with a little looking - get them from one of the three online sources I just mentioned. You don't have to change it very often, tho.

The front-to-back bridge harness is also a little strange, but I've always felt better when I changed it for a Weatherpack anyhow. If you don't expect to do a lot of "swimming," you can also get away with a Molex, or if you want to get nuts, you can use an Amphenol.

The C101 bulkhead connector and the big entry connector above the brake booster on the firewall is a little more difficult, but I plan on replacing them with Amphenols anyhow - mainly because I like them. You can find Amphenols and some decent knock-offs at Allied Electronics.

MSD - www.msdignition.com
Summit - www.summitracing.com
Jeg's - www.jegs.com
Allied Electronics - www.alliedelec.com

Hope this helps! With questions like this, it's easier to give meaningful answers if we know more specifically what you're doing...

5-90

What Im wanting to do is replace the engine harnesses. Wiring and soldering is not my cup o tea...I think my cutting out/dying/hard starting is being caused by one of the harnesses or the many connectors...Going to check out the dealership and local parts houses next week.

It could even be the fuel pump harness, I just need to get some time and get out and look at everything. May try wiggling harnesses from underneath with it running to see if i can get it to die. Dies now when you shut/slam the hood...

Had my radiator rodded out yesterday, getting corroded, was really plugged up, and the original they say. Only did one end cause they were afraid of doing the other. So far so good, running a bit cooler. They had a hell of a time getting it started and such with the dying, hood shutting killing it...blah blah, makes me want to SHOOT the damn thing and put in on a burn pile!!

Cory

i completely "remanufactured" my renix harness ... i got a new harness from a yard and re did every crimp joint which on most the renix harnesses had off the shelf duct tape covering them and were prone to corosion and ick.. anyways the harnesses was completely stirpped all joints soldered and sealed and taped... all the packard electrical connectors were cleaneded with electronices part cleaner and repacked... 3 yrs and no electrical gremlins.... its amazing when u have the entire harness out the engine A LOT of wire .. Also there is a SD report to elimite the C101 connector

Here's some advice from someone who's rebuilt a few engine harnesses...

1) work on a section at a time. It's really amazing how much trouble you can get into if you don't keep yourself working in small sections.

2) Have a set of wiring diagrams BEFORE YOU GET STARTED. Make a copy. Why? It's almost a guarantee that you're going to change a couple wire colours. WRITE DOWN ANY CHANGES YOU MAKE! If you don't, you'll get in big trouble later. Keep a set of originals as are, in case you need to trace something down you'll have a set of diagrams that aren't cluttered up with notes. You can make another set of copies of the clean set, and clean up your nots later - belive me, this is worth doing!

3) You really won't do a lot of soldering. Nearly every terminal you're going to work on will be crimped, but get a set of assembly/disassembly tools so you can take something apart after you put it in the wrong order (trust me, it's going to happen. I've never had it not happen...)

4) A set of OEMR wiring diagrams can be used to generate a list of basic requirements, so you can get (nearly) everything together before you get started. You won't have wiring lengths, but I'd be surprised if you had a lot of wiring proper that needs replacing.

5) A harness is going to be as good as the materials you use to make it. Painless Performance has what is probably the best wire in automotive, and while it's a little more expensive (even in bulk,) it's worth buying. NOTHING is more frustrating that finding out that the "cheap-o" wire you bought is causing you headaches.

6) BEFORE you start to install any wiring, check continuity. Hook up your meter, then shake the wire. This tests your crimps and your wire. It doesn't matter whose wire you use - it's like the "loaded gun" rule. Assume it's crap until you check it YOURSELF. (As I explain the "loaded gun" rule - if God Himself hands you a firearm and tells you it's unloaded, you say "thank you Sir" and check yourself anyhow. Remember, it's YOUR ass - and in the case of wiring, it's YOUR work, YOUR money, and YOUR vehicle. Be picky - it's easier to fix something before it's a problem!)

The only junction that is likely to be a problem for you is the grounds from the fuel injectors - they go to a common ground, six into one.

7) If you've got anyone handy who's good with this stuff and is willing to help, it's not a bad idea to clean up a few things while you're doing a job like this. Where are you, anyhow?

8) If you're doing this for any reason other than age, identify the problem and correct it - if you don't, you'll be doing this again sometime fairly soon.

I know there's a lot of wire involved - I've got the entire electrics for a 1988XJ in a box out in the garage. Folded up and with all the protective crap removed, it's about four cubic feet, tightly packed. Yeah - it's a lot...

5-90

Well, after reading 5-90's posts, I think I will abandon that project... I guess i just wanted the two engine harness, the one behind/below the exhaust manifold, and the fuel injection harness. Is that only one?? or two??, not sure, been over 3 years since i put the motor back in; the harness was routed by the builder through the motor when i picked it up.

Im just going to get underneath and start grabbing wires and hope to find one that when shook will kill the motor. Did this with the wood handle end of a hefty screwdriver on top and nothing happened.

Also, i have taken every connector, plug, relay off under the hood that i could find and did the elec parts cleaner, wire brush, more parts cleaner, then diaelectric grease a couple weeks ago. On the top of the motor and around, nothing below the fenderwells as a reference.

Just need to mess with it, i will find it sooner or later.

I am located in Kearney, Nebraska 68845.

Cory

5-90

have you thought of replacing the C-101 connector with a cannon plug ? this is an idea i have thrown around.... when I did mine i left it in place after cleaning it and repacking it....

I have heard people that were against replacing the factory crimps with solder but i have always thought soldering a connection gives you a better connection with less resistance across the joint...

I did mine with the factory wiring manual, the old harness and my meter next to me

I plan on doing exactly that when I start with my restomods - both to eliminate the "packed" connector (if it's gotta be packed with grease, it's not well designed) and to make the harness more modular for future repairs.

I do NOT solder on underhood connectors if I can avoid it - I just don't like soldering something that is subject to heat. A good crimp is every bit as good as a solder join - by that, I mean a crimp done with the correct tool, preparation of clean wire, and using the correct terminal size for the wire. There's no reason a good crimp can't be done - most of the OEM wiring connections are crimped anyhow - they just use a machine, where I do mine by hand.

It's also easy to tell when I've done extensive work on a harness - I install "permanent" ID tags on everything. I use little 1" brass key checks (the round ones,) mark them with letter stamps, and use a small split ring to secure them to the wiring. Seems like overkill, but I work on things like that with the idea that the next schmuck to work on them will be me, and I won't be anywhere near the shop. The best way to screw Murphy is to anticipate him - the he and his ilk won't show up...

5-90

I might have to use that idea on the tags... I used computer printer lables cvered with clear packing tape they have lheld up for 3 yrs but the brass sounds better