Help with these connectors

[TJones]

I have been driving myself crazy trying to find out what these plugs go to anyone out there able to help? I have been looking at so many wiring diagrams but still can’t find anything. These are from a 1983 gmc k2500 that once was a diesel but now sbc if that matters. These plugs are behind the gauge cluster in the dash

 

[87chevy_com]

id recommend taking a picture of what the front of the connector looks like aswell. The black one might be for the cruise control connector. it would connect to the end of the switch wiring

 

[Jgonick]

1st picture goes to a brake switch for transmission Torque Converter Clutch. - cuts power when brake is pressed (opposite from the one used for brake lights)

2nd. picture is cruise control- plugs into black cable(wire) coming from turn signal lever w/cruise controls).


Attachment shows an example of the 1st one. There are a few slightly different setups depending on the vehicle.

 

[TJones]

1st picture goes to a brake switch for transmission Torque Converter Clutch. - cuts power when brake is pressed (opposite from the one used for brake lights)

2nd. picture is cruise control- plugs into black cable(wire) coming from turn signal lever w/cruise controls).


Attachment shows an example of the 1st one. There are a few slightly different setups depending on the vehicle.

That’s exactly what it was. I just came to that conclusion last night. I ended up taking out my cruise control wiring since it won’t be used and was able to figure this out after clearing up some of the chopped wiring from the previous owner. I got confused because the brake light switch I have in the truck had the cruise control plug to it and the orange and white brake light wires attach to it as well. There was no other spots for that plug to plug into which is bizarre. I am using a b&m lock up kit so sounds like I can just leave that unplugged behind the dash. Are the brake light switches supposed to have 3 different spots for plugs for regular wiring this tcc plug and cruise control plug?

 

[Jgonick]

A few different setups back then. Mainly it would be a brake switch for brake lights & cruise. (Important to understand the two connections on that switch- one cuts power when the brake is pressed down & the other connects power when the brake is pressed down) Another switch was used for the TCC- usually one with a vacuum port used by the cruise control.

In theory if you need the TCC connection, you could put it in the spot of the cruise control connection on the brake switch. (needs to cut power when brake is pressed down)

Attachment shows vacuum brake switch used in cruise control systems & brake/cruise switch

 

[TJones]

A few different setups back then. Mainly it would be a brake switch for brake lights & cruise. (Important to understand the two connections on that switch- one cuts power when the brake is pressed down & the other connects power when the brake is pressed down) Another switch was used for the TCC- usually one with a vacuum port used by the cruise control.

In theory if you need the TCC connection, you could put it in the spot of the cruise control connection on the brake switch. (needs to cut power when brake is pressed down)

Attachment shows vacuum brake switch used in cruise control systems & brake/cruise switch

If I’m trying to hook up the tcc plug and the brake switch what would be a good replacement switch since the cruise control connection won’t work with the tcc plug. The terminals are to close together and the tcc plug won’t lock down onto the brake switch if that makes sense

 

[Jgonick]

You can always remove the terminals from the connectors. Switch the terminals to the connector that works.

Use something like a very small flat head screw driver to push the tang down when you pull the terminal out.