Rear side marker light splice location

[White Stripe]

Im trying to find the location for the positive wire splice for my rear side lights. One of them isn't getting positive voltage. Looking at the wiring diagram it looks like it splices into another wire up the frame somewhere. Anyone know where the splice is?

 

[GA Architect]

FWIW: On my '77 that right rear marker light shares a connection with the license plate lights. That positive wire comes out of the rear loom with the rear combination light wires, and it has a dual female bullet connector.

 

[White Stripe]

FWIW: On my '77 that right rear marker light shares a connection with the license plate lights. That positive wire comes out of the rear loom with the rear combination light wires, and it has a dual female bullet connector.

Sorry I took a pic of the wrong side. Its my left rear that is the problem.

 

[B y r o n]

Have you tried cleaning the ground for that light? A bad ground will prevent it from working.

 

[White Stripe]

Have you tried cleaning the ground for that light? A bad ground will prevent it from working.

Thanks for the reply. Im not getting any voltage on the positive wire in the harness. Ground is good.

 

[nabbasi]

The rear harness is along the passenger side frame rail. It splits and goes to the right/ pass side taillight, up through the floor for the pass side side marker and license plate lights, and the last split goes across the rear bumper/ crossmember then splits for the driver side rear tail light and up through the floor for the pass side marker. Marker light 12V+ should be green.

 

[White Stripe]

The rear harness is along the passenger side frame rail. It splits and goes to the right/ pass side taillight, up through the floor for the pass side side marker and license plate lights, and the last split goes across the rear bumper/ crossmember then splits for the driver side rear tail light and up through the floor for the pass side marker. Marker light 12V+ should be green.

Hi. Thanks. Yes I have followed the harness up the passenger side. I just haven't found where the green wire splices into another wire.

 

[charliemeyer007]

Wire fault tracer $25 on Amoron

https://www.amazon.com/dp/B00P0QKRG6?tag=ihco-20

 

[Living in the Past]

If you left tail light works the problem is in that area. Side marker shares the same wire. Should be simple to trace the wire from the marker down thru the rear of the wheel well to is connection. The hydraulic brake lines and wiring run down the right side on a F engine to keep it away from exhaust. B engines is on the left side to keep it away from the exhaust.

 

[Engineer8000]

The harness runs inside the rear frame crossmember to the rear left corner. Note green wire with double bullet connector.

 

[Engineer8000]

I think the first green wire splice is at the right rear corner, where the right marker light peels off. There may be another one midway across the rear where the trailer plug/switch connect. My harness was pretty hacked up so not 100% sure. You may find PO handywork back there too.

I found this midway across the rear crossmember

 

[Engineer8000]

Also found this in my notes

trailer switch connections, non-hacked up

 

[Engineer8000]

This is my right rear corner, the connector is not OEM, not sure what was there originally but it does suggest there is a splice there.

 

[Engineer8000]

When I rebuilt my rear harness, I had to splice in some non-hacked up wires to get to the left rear. I used some of the double wire bullet connectors as a splice point, that gave me bullet connections for the trailer socket.

 

[Living in the Past]

@Engineer8000 Hey Russ I have a few unidentified wires in my 73 maybe you would like to straighten my harnesses out.

For splices I redo them by soldering them shrink tube. Depending if in a harness I use high quality electric tape to wrap.

 

[GA Architect]

Below is a color coded wiring diagram & connectors for the rear harness that came out of my '77 FJ40.

Below is an updated and simplified wiring diagram for similar years, and is actually the one that is in my rig at this time.

My rear harness wiring set-up.

..

This is the simplified rear harness with a trailer connection that is installed in my 40.

 

[White Stripe]

This is all very helpful. Now I know its unlikely I will have to go into the harness very far. Ive opened up a fair bit of the harness in the rear but will open it up more.