Clearance Lights

[Crumley]

Does anyone know if they are making repoductions of the wiring harness going from the light switch up to the clearance/running light on top of the cab?

[ChevLoRay]

Don't know, but try www.wiringharness.com. This is M&H Fabricators in CA. They make reproduction wiring harnesses for these trucks with correct colors, guages and connectors. They, in my opinion, are your best bet.

[Crumley]

Thanks for the response I will check them out. I may just pull the old harness out and make a new one myself.

[Crumley]

ChevLoRay, I just checked them out, according to their catalog they make make clearance/ marker/ running lights starting in 1973 and newer. I will give them a call tomorrow and see if they can make the harness for 72 and older trucks.

Thanks again.

[tgriffin27]

Crumley where does your wiring go thru the top of the cab on your truck. I think my truck had original clearance lights from the factory. When i bought my truck it had four or five on the cab( I cant remember it has been so long since I took them off) and one wire going up threw a small hole in the top left windshield portion of the cab. I hated to get rid of them but they had been leaking for years and rusted out the drivers side floorboard of the truck. As soon as i bought the truck i took them off. If where my wiring went threw the roof is correct I will look for another set and reinstall them.

[lowrollin70gmc]

How do you get the wiring up to the lights? I'm trying to put a digital gauge above the mirror and can't find a route to put the wires. Thanks in advance.

EDIT: My bad, question answered as I asked. Good to go.

[Crumley]

lowrollinGMC and tgriffin27

The wiring to the 5 marker lights on top of the cab is routed thru the left side A pillar. Starting at the light switch it enters thru a hole just above the left foot well fresh air vent, up the center of the left A pillar. The way to access the wiring comming up the A pillar is thru the hole that the sun visor spring/pivot slids into (remove the left sun visor) and the hole in the top of the cab for the marker lights.

This is going to be a bit of a pain getting this wiring out to repair or replace and pulled back in. I plan on tapeing a pull string onto the marker light wiring so while the wires are being pulled out there will be a string being pulled in the place of the wires. When the repairs are made I will tape the repaired wires to the pull string and hopefully pull the wires back into place.

I hope that made since.

[tgriffin27]

It made alot of sense! Thanks for the info and when it gets warmer I am going to look and see if maybe I have some original wiring going up the A Pillar. The wiring I took out wasn't original at all but the holes in the cab seemed to be original and all where cut the same.

[bignbad]

I think Lmc makes a roof clearnce/marker light harness for the 67-72 chevy/gmc trucks.I rember looking at them for my truck,but i would like to see what they look like on the truck before i by a set. The trucks that came with clearance lights form factory didnt the roof have like pockets for the lights to set in

[72armyswbtruck]

It is extremely easy to reproduce the light harness yourself. If you have the old one to copy, only 2 wires, in a circuit.
Excellent info/idea for the string left behind to follow when you replace the new wiring harness.

[Crumley]

10-4 LMC does have some clearance light repo parts but I didn't see a complete harness, so I ordered some light bulb ends and will repair my existing harness.

I am having to repair the wiring harness due to my stupidity while mechanically wire wheeling seamsealer out of the gutters.....

The truck cabs that came factory with clearance/marker/running lights have pods stamped into the profile of the roof. I have attached some pictures hopfully the roof marker light pods can be seen.