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No reverse lights?

Fordzilla80

Ranger Lariat
6,372
262
Narnia
So,reading fordman76367's thread reminded me about my reverse lights not working on my truck.Here's the story.When I got the truck,most of the rear wires were cut for no apparent reason at all by the previous owner.When I got down under the truck and looked,I traced matches to every cut wire,so I was able to simply reconnect them all.It just seemed like the previous owner cut about a foot of each wire off.After connecting all the wires back together by color(and by checking the wiring diagram),I checked to see if my lights worked.Every light function works except for the reverse lights,and brake.I crawled back under to see if I had missed any wires,but everything was hooked up.I pulled the taillight housing out and followed the reverse lights wiring from the socket to the point where I had to rewire.All the wires seemed to be there,and with a quick check of the wiring diagram,I confirmed it.So I don't know what the deal is.To sum it up,I don't have the reverse lights,and my brake lights don't brighten when I hit the brakes.I'm thinking that the little brake switch on the pedal arm(the little brass thing with the spring inside) might be bad,causing my lights not to brighten.But i'm completely stumped as far as reverse lights go...All help is greatly appreciated.

Here's a pic of the brake switch I mentioned....

D1ZZ-13480-A.jpg
 
Your Backup lights are part of the NSS on the side of the transmission

It is probably full of grease and road grime and needs a good cleaning.

Brake lights:

You probably have a wire with ahort in it.
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Bulbs are all brand new.

The trans is pretty grimy,so i'll go out tomorrow and clean it off and see what happens.

I'll also get under the back of the truck and look through the wiring again.
 
You actually have to remove the NSS and give is complete cleanup.

I use varsol to start then switch to lacquer thinner, then a spray electrical cleaner.

It usually takes 1/2 hour to clean it real good so it works again
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
You actually have to remove the NSS and give is complete cleanup.

I use varsol to start then switch to lacquer thinner, then a spray electrical cleaner.

It usually takes 1/2 hour to clean it real good so it works again

Yea,that's what I meant.I'll make that my project for tomorrow.
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Hey ya'll,If you don't want to read all this down here,then just scroll down to the bottom for the main idea.It might help to read this though so you understand the problem....Thanks.

Well,I went out and thoroughly cleaned the NSS.I put it back on,and tested the reverse lights.They work,but only on the passenger side.Great.I take out the taillight housing on the driver's side,and check the bulb.It's brand new,and the filament isn't blown.I hop in the truck and turn on my lights.The rear brake lights come on.Okay,so it must be something with the reverse light socket and wiring that's keeping it from working.I check the ground,and notice the screw is stripped,and loose.The previous owner must have tried to undo the ground at one time and stripped it.I grabbed my vice grips and get the screw out.When I go to grab the ground wire,the ring terminal breaks off.So I strip the wire and put a new one on.I test the lights again.Taillights work,but still no reverse light on the driver's side.Okay,so my next step is to look for disconnected wires,or shorts.I pull the wiring harness out from the bed and chase the wires all the way to the harness plug in.None of the wires are damaged,and everything is connected.I disconnected the rear light harness,and tested the female plug for voltage.It does indeed have voltage going to the rear harness.So I go back to the reverse light socket and try to see if the wire is loose in the socket.Nope,it's tight.Then I notice a bulge in the wiring about 4 inches from the reverse light socket.It's got some kind of adhesive black cloth wrapped around it.

MAIN IDEA...

When I pulled the cloth off the wire(see above),I found 4 wires that are all connected to each other,without a connector.It looks like somebody took the wires and wrapped them around each other,and then taped it.I definitely don't think this is factory.One of the wires goes to the reverse light socket,two go to the harness connector,the other one goes to the ground strap.Can anybody tell me if this is wrong,or if it's supposed to be this way?I tried looking at the wiring diagram in my Hayne's manual,but it wasn't any help at all,since it doesn't seem to list any of the colors that I have.I think this little group of wires is what's screwing up my driver's side reverse light.All help is greatly appreciated.Thanks!
 

1985 Ford F-150

Country Boys Can Survive
7,816
307
Tooele, Utah
That sounds like the problem Id cut em and strip em to get some good wire then re connect em usin some sauderless connectors or whatever ya prefer and try it.
 

1985 Ford F-150

Country Boys Can Survive
7,816
307
Tooele, Utah
Well the only other thing I can think of is new bulbs. Even though they look good sometimes theyre not. My dome light didnt work on the 72 for a long time then I looked at it and the bulb looked good but I replaced it and it worked.
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
I swapped the taillight bulb in and had nothing.Right before I took the taillight bulb out,I tried it,and it worked.Then after I swapped it to the reverse light it didn't.Swapped it back to the taillight,and it worked.

I'm kinda confident that it's those 4 wires that were connected funny.
 
78wiringdiagram-1.jpg


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86

86wiring.gif
 
Last edited:
Did you at least separate the wires ?
 
So you need to identify the colour coding of the wires that are there and post that info.
 

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