1983 GMC K1500 electrical connector just above steering column near firewall identification help

[jj81]

Hello,

I am rewiring with American Autowire's full truck kit update. However, looking for some help to ID this connector in the pictures (these pictures are the old stuff I removed). I removed all the wiring, retained it for just in case something would happen. I however, I started this project a couple of months ago, had to order more parts before moving forward, got busy with work and life. Now I'm back at it, kind of forgot a little about this piece...the rest of the truck I'm good to go, just this one is eluding my mind at the moment. Also, the American Autowire kit doesn't seem to reference this component or have a replacement with this update...that I can tell so far.

1983 GMC K1500 4x4, 305, TH350. No cruise, power windows or A/C...pretty barebones model.

This white connecter (female) is located right at the firewall inside the cab
Just right above the neutral drive switch
I have the black connector (male) I pulled out of it, with the wires going in a couple of different directions back to the fuse box and through the firewall into the engine bay.
There is a plastic cylinder butting up the wires in and out.
The green wire ends at an orange connector.
I tend to remember this being on the inside and not the engine as I have not pulled any grommets just yet. But, I am kind of losing were it goes after that.

Any ideas, what this is for? Thank you in advance!
Josh

 

[jj81]

Update, doing some more research, I believe it could be this?

You must be registered for see images attach

 

[hack_man]

I was hoping I'd be Able to help but mine is a 1983 K10 4X4 305 with 4 speed manual transmission, also barebones but I don't see that connector.

 

[jj81]

I was hoping I'd be Able to help but mine is a 1983 K10 4X4 305 with 4 speed manual transmission, also barebones but I don't see that connector.

I appreciate you looking into it. It looks like I have to take the old setup and transfer it to my new setup. I'm just a little lost on the part that goes through firewall, into the eng bay, and where it goes from there...could just be that I don't need it and it is indication purposes only. Something for later on down the road. The 4x4 is all mechanical anyways.

Hack man, just curious, there are 2 lights in line with the connection down to the transfer case, one for the 4wd shifter console but I don't see where the 2nd light goes, supposedly upwards in the dash (troubleshooting backwards from the connector)?

Thanks again

 

[hack_man]

I appreciate you looking into it. It looks like I have to take the old setup and transfer it to my new setup. I'm just a little lost on the part that goes through firewall, into the eng bay, and where it goes from there...could just be that I don't need it and it is indication purposes only. Something for later on down the road. The 4x4 is all mechanical anyways.

Hack man, just curious, there are 2 lights in line with the connection down to the transfer case, one for the 4wd shifter console but I don't see where the 2nd light goes, supposedly upwards in the dash (troubleshooting backwards from the connector)?

Thanks again

Are you maybe referring to the Speedometer cable? It looks like an electrical cable and attaches to the transfer case and feeds up to the top of the dash to the speedometer. I'm actually replacing mine right now.
The other line I think you are referring to is for the light that illuminates when 4H or 4L is selected.

 

[Broken85]

This looks like the diagnostic port for the lockup TC. I think you are supposed to ground this out to manually disengage the lockup or something.
I know on a 700R4 there is. Blue and green that engage and disengage the lock up TC from the vacuum switch

Don’t hold me to it. Good luck

 

[Jgonick]

I'm not familiar with the TH350, Did your truck originally have a 700r4 transmission? All that wiring is dealing with the Torque converter lockup in 700R4 transmission. & yes, The orange port is just a test port for diagnostic purposes.

FYI- RPO MD8- refers to 700R4 in your attachment of the wiring.

 

[jj81]

I'm not familiar with the TH350, Did your truck originally have a 700r4 transmission? All that wiring is dealing with the Torque converter lockup in 700R4 transmission. & yes, The orange port is just a test port for diagnostic purposes.

FYI- RPO MD8- refers to 700R4 in your attachment of the wiring.

TH350 I believe since day 1 40+ years ago, I think the VIN supports that thought as well. I was digging into the schematics, one page down and found something closer to my setup. But your info is correct and seems to closely the same for TH350, 400 and 700R, just the ends are a little different. See my next post, I think I'm very close.

 

[jj81]

I believe I mostly have it all figured out. The only part that has me confused, on the American Auto Wire fuse block, were do I re-plug the Gray wire (with green connector and is for the light of the shift lever console)? On the old fuse block, it was connected to the lower left spot named "LPS" (Limited Power or lamps meaning maybe?). On the new American Auto Wire fuse block, that same location is now named "BAT", is this the same or do I need to use a different slot, like ACC?

I found this thread from last year, that helped me confirm that this is all one sub harness and that American Auto Wire did not account for this option on trucks with 4x4. My old sub harness is still usable...I just need to find a spot on the block to put that one wire into.

https://www.gmsquarebody.com/threads/4wd-indicator-light-wiring.29165/

 

[Jgonick]

I re-plug the Gray wire (with green connector and is for the light of the shift lever console)? On the old fuse block, it was connected to the lower left spot named "LPS"

The INST LPS on original fuse block gets power from the pull headlight switch (via DK GRN-44 wire.) . The LPS INST fuse feeds the LPS slot on fuse block along with your dash lights (and backlights for radio etc . by GRY-8 wire.)

BAT would always be on. ACC would always be on when key is turned.

I'm not real familiar with the American Autowire's full truck kit update- I would look to see where your dashlights are connected to it and go from there.

 

[Jgonick]

To me the simplest would be to splice it to the gry wire running to radio (radio's backlight when lights are on). If you have an aftermarket radio there is a good chance that wire isn't even being used. As you can see in the diagram I located, that gry wire is labeled "dash light" at the radio.

 

[jj81]

To me the simplest would be to splice it to the gry wire running to radio (radio's backlight when lights are on). If you have an aftermarket radio there is a good chance that wire isn't even being used. As you can see in the diagram I located, that gry wire is labeled "dash light" at the radio.

Ohhh, that is awesome, thank you so much!

 

[Matt69olds]

Before cutting and splicing anything, read the instructions again for the harness. I wouldn’t be surprised if there is a cavity in the fuse box for dash lights.

If you don’t see anything in the instructions, call American Autowire.