black is grounds. no ground = no lights.

Sorry I didn't add that earlier. I edited the earlier post to add that.

Unless you plan on towing in the really near future, get rid of the mess and take the trailer harness off. Get all the lights working right, then worry about adding a trailer harness.

 

I'm thinking the same thing - remove the trailer lights all together and add them back in later, if needed.

So related questions: Since i have unplugged the trailer harness, should those plugs just be hanging there, or should they be plugged back into something, if that makes sense.

 

In general, there should be no hanging plugs or dangling wires or anything - not underneath, anyway. Perhaps pictures would be helpful - upload 'em to one of your Albums, then use the BB Code (will be in a text box below your uploaded picture(s)) to put your pictures into your posts here.

User Gallery & Picture Display Help - Ford Truck Enthusiasts Forums

 

Sorry it's taken a while to get back to everyone - busy work week.

Anyway, here is a picture of the wiring under the truck (assuming I correctly uploaded the picture). You can see here that there are three plugs that are hanging (They are at the top of the photograph). This is where the trailer lighting harness was plugged in. There doesn't appear to be anything to plug into these plugs where I disconnected the trailer lights.


here is the trailer lighting harness plugs that I disconnected. I'm not sure if this picture is useful at all. These are connected on one end to the trailer outlet:




Anyway, like I said, I'm not sure what to do with these empty plugs. Is this a bad hack job, or is this how things should look under there. Thanks as always

 

If anybody is still checking this thread, here is a follow-up: In looking more closely at the harnesses up there, it appeared that I just need to switch some things around, as whatever make-shirt trailer harness the PO had installed wasn't completely removed yet. The result: Partial success. I have turn signals, running lights, and brake lights on the back end again, but I still have no reverse lights.

I tested the wires coming INTO and OUT OF the harness the connects the neutral safety switch with the key set to on, and the truck in reverse. I had power on BOTH sides of the NSS. I test the wire coming into the rear wire harness (the last 'plug' before the wires head into the reverse light sockets). I had no power on either side of the harness. Something, it appears, is wrong between the NSS and the plug. Is there anything in between where the reverse lights would go? Or is it one complete run from NSS to the final plug?

 

It's a straight run to my knowledge.

Some people have found really corroded wires with broken insulation along that run....

 

Hey Jeff, good to hear. And sounds like you've got a cheap fix! I'd take that over easy.

I got under my truck to get pictures for you, but mine is totally different. Looks like I have an aftermarket rear harness. But I did search, and between my R switch and the rear is uninterrupted. Then I figured auto would be different. In the Hayne's (not that it's a great resource) I see a straight shot for 86 auto trucks.

Is the wiring exposed so that you can examine all of it? If not what I'd do is solder, or at least tape, new wire to the light end, then pull until you get new wire at the NSS side. Hook it up and you should be golden.

Glad you're getting it worked out. When do we get pictures?

 

I'll be investigating today or tomorrow to see how hard it is to access the wire going from the NSS to the back of the truck. Hopefully it's not too tough, but I haven't really looked closely yet. If it is, I guess I'll be learning how to solder! I'll let you guys know how it goes...

And Dave, I'll get some pics up ASAP.

 

Resurrecting this thread I hope,

Just wondering if anyone knows what the purpose is for all these wiring harnesses???

I am working on wiring right now in the rear end and I would like to know what they are for.