Cole Rodgers

Alright, I'll get straight to the point. I'm currently fixing my stock (for now) XJ that i recently bought from an older man who had slightly crashed it. Anyways, I've gotten to the point where I'm reassembling the front end and putting the headlights in, and before I finished, I tested the lights to make sure they worked. Only a few of them worked, so I swapped bulbs (right to left and left to right) to test if the bulbs were bad. Well, the lights that worked didn't work on the other side. When i pulled out the bulbs, I noticed that the harness was corroded pretty bad. At this point I think I would be better off buy a new harness, but can't seem to find one anywhere. Any ideas where to look or what to do?

ijeeep

Install an upgrade headlight harness, the kind with two relays. You'll kill two birds with one stone. It'll solve your problem and be hands down the best $25 you can spend on an XJ

Cole Rodgers

So if I buy the Ksuspension harness upgrade for 25$, that should fix the lights not working even with the corosion?

cruiser54

Harness corroded or damaged?

Saudade

The KSuspesion harness plugs into the factory harness on the passenger side. If that's the side that corroded, you'll still need to fix that or directly splice the 2 harnesses together, depending on the extent of the OE harness damage. Depending on the nature of the damage, you may want to still clean up the bad side.

You can find the KSuspension harness here:

https://www.ksuspensionfab.com/store...Harness.html#/

There are also cheaper harnesses sold elsewhere but are not domestically produced.

Cole Rodgers

I guess my main question is where can I buy a new OEM harness, if that's even possible?

Saudade

New OEM? Not likely. Used? Try ebay or a local salvage yard.

You can go to https://www.moparpartsgiant.com/. Enter the year/make/model for your XJ, then look in the electrical section. You'll find the part number. You can then use that to search for a replacement harness. If you're lucky, you may find one.

Replacement 3 pin connectors for the headlamp are readily available if the corrosion is just in the connector.

ijeeep

The factory wiring was almost adequate, not optimal, when they were brand new.​​​​ There are no NOS harnesses available anymore.
The newest used harnesses out there are 25+ years old now and will have the same age induced resistance creep and voltage drop as the rest of them.

It would be time consuming and somewhat expensive to make a replacement harness but not hard. That could be worth a point or two in restoration car show competition.
It would be an esthetic repair but not a restoration of the headlights function to original brightness like the day it rolled off the assembly line.

Cole Rodgers

Would it be worth taking the risk with buying a used one off of Ebay or out of a salvage yard compared to cleaning my current one and hooking up a volt meter to measure if I'm getting power and replacing the non-powered wires? Heres a couple of links I found on Ebay
Harness 1
Harness 2
Harness 3

cruiser54

Why not use an ohm meter on the one you have?
Find out where the issues may be and fix them?

lawsoncl

Unless the wires are cut or corroded to the point of no connectivity, the k-suspension harness (or the same thing off eBay for $15) will likely solve the problem. The relays in the harness don't need much current to switch, o even a poor connection will work.

ijeeep

Yup.

The upgrade harnes leaves the factory wiring headlight switch and hi/lo beam switches to provide a light ( no pun intended ) control "signal". The upgrade harness and relays carry the load and take the wear & tear instead.

Cole Rodgers

Even with the harness upgrade from Ksuspension, there would be no power to the lights if the wires are either damaged or the bulb sockests are corroded, right? Proving useless until the oem harness is function, or am I completely wrong on this and the upgrade harness connects directly to the battery, providing power...?

lawsoncl

A high resistance connection in the original wiring wouldn't work with the headlights which need almost 10-amps, but might drive the relays on the new harness which need around 0.1 amp just fine.

ijeeep

Upgrade harnesses take the full amount of juice direct from the battery and feed it through a pair of relays directly to the headlights.
​​​​​
The existing headlight and high beam low beam switches and wiring are now used to control the high beam / low beam relays (which carry the full load)