Bought new tail lights, wiring doesnt exactly match up.
 

My truck had a generic set of trailer lights on it and i bought the right tail lights for it from brothers. They aren't plug and play, I have to solder them. But I knew that. Didn't want to spend $50 each for oem tail lights just to get the right plugs. The factory tail light wiring harness is showing only two wires, a yellow and brown. And my new tail lights have three. A red, black and white. Now I assume the black is for ground and red is for power, but anyone know what the white would be for? But since there is no 3rd wire on the harness, where would I connect the 3rd wire on the tail lights?

Re: Bought new tail lights, wiring doesnt exactly match up.
 

Whats the truck? What year? Fleetside or stepside ?

Re: Bought new tail lights, wiring doesnt exactly match up.
 

I did the same thing you are doing on my stepside, but I can't rember the colors. I bought the lights at O'Reilly's and it seems like there was a diagram on the box.

I don't think any of the wires are ground. Seems like i remember one wire is tail lights, one is brake/turn signal, and the last one is for your reverse lights. I believe white is going to be the reverse light. They get their ground from bolting to the bed. I also had to run a ground strap from the bed to the frame to get my lights to work properly.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

Factory wire colors are:

Brown = tail lights (both sides)
Yellow = Left rear turn signal & brake light
Dark Green = Right rear turn signal & brake light

Did the new lights come with a diagram or color code chart? A lot of trailer wiring uses white (instead of black) for the ground.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

It's an 83 stepside and no, these new tail lights came with no diagram. I pulled out the tail light harness and took off all the electrical tape and man, these wires are cut to hell. Whoever messed with them did a terrible job. And there are three wires each on the factory tail light harness. A yellow, green and brown. So now I just need to figure out with wires on the new tail lights go to which wire on the harness. The wires on the factory plugs that go from the tail light to the harness were cut right at the base of the plug, so I really have no way to fix it. and I don't think they sell them new. So I think I will just have to crimp on some female plug in to fix it.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

Hook them up and if the tail light is on when they are hooked up and does not get brighter then switch the wires around. If it does get brighter then you are good to go. To figure out the turn signal light use a light tester.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

Since we are talking tail light wiring. I was putting my wiring back on the frame last night and noticed a burnt section. I cut out the bad spot and noticed there is a dark and light green wire along with the yellow and brown wires. What is the extra green for?

Re: Bought new tail lights, wiring doesnt exactly match up.
 

light green to both backups
yellow to left blinker
dark green to right blinker
brown to both parking lights/plate light

Re: Bought new tail lights, wiring doesnt exactly match up.
 

Thanks. Much appreciated.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

I think I am going to love this site! I will be wiring new tail lights on when I get my truck back and this is great information to have going in. I was having trouble finding tail lights for a step side that were a decent price so I picked some up from Advanced and was wondering how the wiring would match up.

Thanks for the info!
Tim

Re: Bought new tail lights, wiring doesnt exactly match up.
 

This snipped step-side taillight wiring diagram should help. The whole 83 CK wiring diagram is in my sig.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

That's perfect Hatzie, I stopped by the paint shop today to take a look at my tail light wires and this matches exactly.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

I changed the ones on my 81 stepside. the stock ones had a plug with 3 spades inside. the wires did not match up. so what I did was I made up some female spades for the taillight side, and just kept moving the wires around till I got it right, and then when to the next one. I never poped a fuse or melted any wires they were led ones from xyz parts store.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

If you have a damaged molded plug on a 1973-1983 truck you can convert to the 4 position 2x2 square Weatherpak plug and socket that GM used on the later squares. I've done it with a couple trucks.
This is the 1985 tailight diagram. The terminal pinout should be the same all the way to 1991.

• Circuit 9 = Tail LPS
• Circuit 19= RH Turn
• Circuit 18= LH Turn
• Circuit 24= Backup LPS

http://johnnynightstick.s3.amazonaws...0Tailights.jpg

2x2 Weatherpak Plug and Socket BOM with extra terminals and seals for one 2x2 square weatherpak (Click on This Mouser Electronics Project Link and add to cart to order)

• 1 ea 12015024 4P MALE BLACK 20 AMP DELPHI WEATHER PACK CONN SHROUD (Chassis Harness)
• 1 ea 12015798 4P FEMALE BLACK 20 AMP DELPHI WEATHER PACK CONN PLUG (Lamp Harness)
• 10 ea 15324982 DELPHI WEATHER PACK INDIVIDUAL LOOSE CABLE SEAL GREEN
• 5 ea 12089040-L DELPHI WEATHER PACK INDIVIDUAL LOOSE TERMINAL MALE TIN PLATED WIRE DIA .8mm²-.5mm²
• 5 ea 12089188-L DELPHI WEATHER PACK INDIVIDUAL LOOSE TERMINAL FEMALE TIN PLATED WIRE DIA .8mm²-.5mm²
  
  If you are working on a Stepside use three 2x2 connectors instead of the splices the factory diagram shows. Two will have 1 cavity plug each... at $0.22 ea I usually get at least 1 extra JIC one goes rolling under the bench.
• 3 ea 12010300 DELPHI WEATHER PACK INDIVIDUAL LOOSE CABLE CAVITY PLUG GREEN (Mouser stocks this)

Tooling

• 1 ea 12085270 Delphi Ratchet Crimping Tool 20-14 AWG for most Delphi Weather Pack and Metri Pack Terminals
• 1 ea 12014012 Weather Pack Terminal Removal Tool

Tooling If you're only doing a few...
http://www.amazon.com/Delphi-Packard-Weatherpack-C...

Re: Bought new tail lights, wiring doesnt exactly match up.
 

That's what i'm doing. Problem is my turn signals work, but are very dim. and I can't get the back up lights to work. checked all my fuses and they're all good. brake lights will work fine. Do you happen to remember which color wire on the taillights went to which color wire on the harness?

Re: Bought new tail lights, wiring doesnt exactly match up.
 

not sure where each wire went. Not sure how much time you have to get this done. I wont get to my stepside to check till Tuesday. but I do remember that the colors were not the same on either side like the truck had a black,green and red or something and my lights had like yellow red and brown. are the lights on the truck? im not sure if it matters cause mine had a wire inside going to the studs that they bolt on to for a ground so maybe your dim issue is a ground problem.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

I have all the time, this is just a project so it sits. These taillights have a brown, red and white color wires and my factory harness was brown, green and yellow.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

you can test it with a nine volt if its out ,
I've seen the ground tab rot out back there,wouldn't know there was ever one
check it for strength

Re: Bought new tail lights, wiring doesnt exactly match up.
 

Hatzie,

Thanks for posting both of those diagrams. I have an 86 frame with an 83 bed and the connectors are different. 86 has the square plug and the 83 has the round plug. The diagrams you posted helped me make an adapter for my harness.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

No problem. That's why I posted them. :D

I'm not a big fan of the old molded plugs. They don't keep water out so the connectors can become a collection of corroded terminals even with dielectric grease.

I'm not sure why GM didn't use 4 position Weatherpak connectors with cavity plugs, like the fleetside harness, on the 1984 and up step-side tail lights. When they made the change to Weatherpaks they would've only had to buy a long and short bulkhead to tail harness for Fleet and Step models rather than four different harnesses for the Long Fleet, Short Fleet, Long Step, and Short Step models. I believe the 2x2 Weatherpak plugs have provision for a mounting tang too. Maybe they had a large inventory of the step-side taillight assemblies that already had the molds.

Re: Bought new tail lights, wiring doesnt exactly match up.
 

so sorry this took so long to get for you. Been busy with snow, parts store, and starting my first EMT job.... but got some pic for you

Looks like on the lights have the brown on top yellow down off to the right and red on the bottem

the truck side has green on the bottem black on the top and yellow off to the side. the truck pic sucks i tried like 10 times to get to even that little clarity

hope this helps let me know if you need more info

Thanks
Kserieskid

Re: Bought new tail lights, wiring doesnt exactly match up.
 

sorry forgot the pic