OEM Headlight Harness Build *Not a relay upgrade*

[comanche1989]

Hi All!

 

After a long hiatus from the group, I have finally gotten my Comanche through highschool, college, early career, ect.. to a place in my life where I have the time, space, and resources needed to actually work on it (beyond keeping it limping along). 

 

Shop and Comanche pictures below:

 

 

I am the worst at taking pictures however I wanted to share some data around the factory front lighting harness. While many people upgrade the headlight harness itself, that still leaves the old plug to the engine harness in place, which is always crusty. 

 

Prior to upgrading my headlight harness to the relay set up, I wanted to make sure I had a clean start up front. 

 

In order to access and pull the harness out, what I have found easiest is to pull the header. Note that the screws/ bolts/ nuts for the header and molding can be quite rusty. Would suggest soaking with penetrating oil.

 

Pg. 1989-1990 in FSM

 

When you remove this, the wiring harness if installed as is from the factory should come out with it. 

 

 

From here, remove all connections to the lights and remove the wiring harness from the header. Before removing any tape from the harness, I would suggest drawing the outline of the harness on a piece of cardboard so you can match the final shape with your new harness.

 

Finally, to build the new harness, here are the parts I used, as well as shrink tubing, butt connectors, and solder:

 

Item	Manufacturer / Brand	Part number / Type
Full-size turn-signal socket	Dorman	85898
Headlamp adapter sockets	RED WOLF	H4 / 9003 / HB2 female, 2-piece kit
Side-marker socket and cable	Crown Automotive	J5455853
Main disconnect connector	N/A	10-pin Deutsch-style connector
16 Gauge GXL Wire	N/A	Wire

 

The way I built my new harness was simply one wire at a time, tracing, copying, and splicing into the new connectors. However, after making the new harness I also measured and mapped each section of wire. The attached excel spreadsheet shows the measurements, circuit key, as well as the manual references for the wiring diagram. Please note that I did not measure precisely, however the measurements should still work to build off of. 

1989_Jeep_Comanche_Front_Lighting_Harness_With_Parts.xlsx

Once built, I would suggest using 1/2 cloth wiring harness tape to bundle the wires, using the carboard pattern you made early to keep everything tidy. After that, install, and enjoy a new harness that should last another 36 years :) (Don't mind the crazy mess)

I will continue to work through other wiring harnesses on the truck and share additional measurements with the group.