Taillight Harness Rebuild and Sockets

[Torq_Shep]

I have been a way for a few years but I am preparing to go grab my truck from a few hours south of here in the following few weeks. I have fairly substantial wiring issues with the truck but I think I can fix it enough to get it from Boring, OR to Seattle, WA.

 

One of my major problems is that there is a major short in my taillight circuit. I am assuming it is the taillight harness but it could be anywhere in that circuit. As I do not have the truck here I started looking at a harness I pulled off my parts truck and put in a box years ago. One thing I did was to find as many of the parts of this harness that I could find but I still have more work to do.

 

It is probably documented somewhere on here but I think I found the following cross references:

Stop Lamps and Rear Markers:

- GM 12003759 *Only the GM one has a gray housing like the original. the others are beige housings. 

- Standard S502 looks to be correct but it is not using Aptiv/Delphi parts to assemble. Housing is light tan, no markings, wiring is AVS 0.85 metric wiring vs TXL 18ga, and the socket pins are not knurled like the Delphi. Adequate product just not as good as original. 

- AC Delco LS253 ** Does not directly fit. The pins and back plate are the same but the tabs are slight off. Best I can tell these are Aptiv/Delphi 12089345 Housings.

 

- Aptiv/Delphi Housing: ????

- Aptiv/Delphi Ground Pin: 08917863

- Aptiv/Delphi Terminals: 08917861

- Aptiv/Delphi Gasket: 12020720

- Aptiv/Delphi Back Cover: 12077444

- Aptiv/Dephi Bulb (if you would ever want that): 09438848

 

 

Reverse Light Socket:

- GM 12027133 

- May be an AC Delco LS50

- May be a Dorman 85869

- May be a BWD S9156

- May be a Standard Ignition S-768

 

 

License Plate Light Socket:

- GM 12083460

- Likely an AC Delco LS32

 

What I do not have is the 1991-1992 6pin connector cross reference.  I also wish I could buy the sockets as pins and housings to crimp my own wire into but I doubt I will have any luck there. 

 

If anyone wants to chime in and help or if someone has already done a bunch of cross referencing work I am VERY interested for the entire truck and not just the rear harness. 

 

I am also debating building cab back harnesses or having them built. The parts aren't cheap but the cab back harness seems to be falling apart on every one of these trucks. If there is significant interest in this I will put together a bill of materials for these harnesses and get a quote on getting them done (or do them myself). 

[ghetdjc320]

Interesting, you mind if I cross post this info into the thread I’m compiling on all the different connectors? BTW, I went with a painless chassis harness. Had to re work a few of the circuits but much of it was plug and play. Routing and trimming wiring took up the majority of the time as it’s a universal harness. 

[Torq_Shep]

Sure thing! 

 

Glad to see you are still around. Last I recall you were doing a Holley ECU right? I am planning to do a late JTEC but I am curious on what you did. I will probably go read your posts later =P

[AZJeff]

9 hours ago, ghetdjc320 said:

Interesting, you mind if I cross post this info into the thread I’m compiling on all the different connectors? BTW, I went with a painless chassis harness. Had to re work a few of the circuits but much of it was plug and play. Routing and trimming wiring took up the majority of the time as it’s a universal harness. 

The wiring for the back of a Comanche is so simple that one can make their own harness pretty easily.   I chose to use an AMP weatherproof connector, but a Deutsch weatherproof type would work equally well both where the wiring leaves the cab, and where it spreads out for the various sockets.

 

SOLDER all of your connections, and use adhesive lined heat shrink, and you should be good to go.

[Torq_Shep]

1 hour ago, AZJeff said:

The wiring for the back of a Comanche is so simple that one can make their own harness pretty easily.   I chose to use an AMP weatherproof connector, but a Deutsch weatherproof type would work equally well both where the wiring leaves the cab, and where it spreads out for the various sockets.

 

SOLDER all of your connections, and use adhesive lined heat shrink, and you should be good to go.

 

I agree, the harness in the back of the truck is pretty easy. I am starting there but I am eventually going to do the cab and engine as well. The universal kit will get me there when I get to that part but I am also considering just mapping the harnesses and having them quoted for assembly. Biggest issue would be building a test fixture to make sure the assembly was correct. 

 

From building construction equipment, I generally try and terminate at a plug whenever possible. The number of "gotchas" when building a harness is kind of insane and you won't know until it comes back to my desk as an RMA =P

 

I just bought the knockoff Deutsch crimper to do this and a bunch of other stuff on the truck. Need to go and buy the pins but I have a number of housings. 

 

https://www.jrdtools.com/products/jrready-new-dt1-crimp-tool-hdt-48-00-equivalent-drk-rt1-hook-drk-rt1-screwdriver-for-in-automotive-motorcycles-trucks-repairing-maintenance

 

I prefer the Deutsch over the Metri-packs just because I think the pin connection is a lot better (basically impossible to not get right) and you can buy 1 piece pins that don't spread out overtime. 

[AZJeff]

1 hour ago, Torq_Shep said:

 

I agree, the harness in the back of the truck is pretty easy. I am starting there but I am eventually going to do the cab and engine as well. The universal kit will get me there when I get to that part but I am also considering just mapping the harnesses and having them quoted for assembly. Biggest issue would be building a test fixture to make sure the assembly was correct. 

 

From building construction equipment, I generally try and terminate at a plug whenever possible. The number of "gotchas" when building a harness is kind of insane and you won't know until it comes back to my desk as an RMA =P

 

I just bought the knockoff Deutsch crimper to do this and a bunch of other stuff on the truck. Need to go and buy the pins but I have a number of housings. 

 

https://www.jrdtools.com/products/jrready-new-dt1-crimp-tool-hdt-48-00-equivalent-drk-rt1-hook-drk-rt1-screwdriver-for-in-automotive-motorcycles-trucks-repairing-maintenance

 

I prefer the Deutsch over the Metri-packs just because I think the pin connection is a lot better (basically impossible to not get right) and you can buy 1 piece pins that don't spread out overtime. 

I am a lazy @$$.  I buy the connectors with pigtails already attached, and then crimp/solder/shrink wires on to the connector pigtails to make my harnesses.  Your method is more elegant, but requires the added tools to crimp, plus the special tools to remove a connector pin if you screw up and need to replace it.

[Salvagedcircuit]

10 minutes ago, AZJeff said:

I am a lazy @$$.  I buy the connectors with pigtails already attached, and then crimp/solder/shrink wires on to the connector pigtails to make my harnesses.  Your method is more elegant, but requires the added tools to crimp, plus the special tools to remove a connector pin if you screw up and need to replace it.

This is the way

Knowing that the certified molex crimping tools go upwards of $300 for one variant of a connector, I don't bother crimping my own. I just get a pigtail, solder and adhesive heatshrink. I try to get the pigtails from digikey, mouser or some stp part number.

[Torq_Shep]

On 6/18/2024 at 7:09 PM, Salvagedcircuit said:

This is the way

Knowing that the certified molex crimping tools go upwards of $300 for one variant of a connector, I don't bother crimping my own. I just get a pigtail, solder and adhesive heatshrink. I try to get the pigtails from digikey, mouser or some stp part number.

The cost of the crimpers is absolutely insane... Generally, for repairs, pigtails are just fine. I am on the fence on if I want to start doing some harness work on the side which is why I am starting to invest in the tools. 

[Torq_Shep]

So a few more notes just to make sure I write them down somewhere. 

 

All of the wires in the harness are 20ga 16strand copper except for a 16ga 19strand ground wire that also feeds into the harness for the fuel pump. All of the wiring has sheath thickness indicative of "TXL" automotive wiring. 

 

From what I can see, the single ground at the very back of the truck is the only ground for the rear lighting and the fuel pump... The power wire for the fuel pump itself is also 16ga.

[SCJ Steve]

Just an FYI, I recently "refreshed" my rear light sockets. Typically, they're packed with what looks like peanut butter, but is really just a 30-something-year-old grease. It wasn't by any means a quick job, but I was able to get them looking pretty much brand new and packed them with fresh dialectric grease. Lots of picking, scrubbing, then more picking and scrubbing. Totally worth it in the end though. I'm actually considering selling sets of them and charging a core, so I could constantly be refreshing them and getting them back out to MJ owners. Here's a before and after of how they look!

[Torq_Shep]

23 hours ago, SCJ Steve said:

Just an FYI, I recently "refreshed" my rear light sockets. Typically, they're packed with what looks like peanut butter, but is really just a 30-something-year-old grease. It wasn't by any means a quick job, but I was able to get them looking pretty much brand new and packed them with fresh dialectric grease. Lots of picking, scrubbing, then more picking and scrubbing. Totally worth it in the end though. I'm actually considering selling sets of them and charging a core, so I could constantly be refreshing them and getting them back out to MJ owners. Here's a before and after of how they look!

I scraped the chunks out and threw them in an ultrasonic. Generally the housings seem to be okay it's the wiring on mine that is so dried out that it cracks when you bend the wires. 

 

Btw. Mouser has the Aptiv/Delphi seals still available. 

[SCJ Steve]

14 hours ago, Torq_Shep said:

I scraped the chunks out and threw them in an ultrasonic. Generally the housings seem to be okay it's the wiring on mine that is so dried out that it cracks when you bend the wires. 

 

Btw. Mouser has the Aptiv/Delphi seals still available. 

Yup, I came across this post when I was trying to find replacement sockets and saw that the gaskets were available as well. Just placed an order for six of them. Thanks for tracking all of that down! Very helpful post!

[A-man930]

This is great stuff. Thanks for posting

[Torq_Shep]

9 hours ago, SCJ Steve said:

Yup, I came across this post when I was trying to find replacement sockets and saw that the gaskets were available as well. Just placed an order for six of them. Thanks for tracking all of that down! Very helpful post!

 

If the gaskets also work for the reverse lights please report back. Those are a different socket technically although I assume the gasket is similar enough. 

[SCJ Steve]

13 hours ago, Torq_Shep said:

 

If the gaskets also work for the reverse lights please report back. Those are a different socket technically although I assume the gasket is similar enough. 

Will do. Should have them in a few days.

[A-man930]

Are replacement terminals available for the sockets? 

[Torq_Shep]

8 hours ago, A-man930 said:

Are replacement terminals available for the sockets? 

Only if you want to buy 1000+ of them at >$1 a piece... 

 

The ACDelco LS253 has pre-crimped terminals that are the real Delphi pins but they are unfortunately pre-crimped. The back plate is a real Delphi part but the housing is incorrect. 

 

The aftermarket sockets (Dorman and Standard) use okay terminals but they are not knurled at the lamp socket like the real Delphi ones. Otherwise they are identical.