VSSB Drac wiring question

[Tim Bro]

Good day,
I was hoping to ask for some help with a wiring issue. I bought a 93 GMC Sierra C1500. No engine, no trani. According to the VIN & rpo codes, it originally came with a 4.3 and 5 speed manual. At some point there was a previous engine swap. But, no engine or trani now. 7 pin VSSB is behind the glovebox. There look to be 2 different sets of VSS wires hanging off of the firewall over the trani tunnel. Both are 3-4 ft long. I have a LT GRN/BLK & PPL/WHT twisted pair with a VSS plug on the end. It passes through the firewall on the passenger side, by the ECM. It looks a little hokey because of the hole that was made in the firewall. I also have a YEL & PPL/WHT twisted pair that has a VSS style plug on the end. It passes through the firewall on the drivers side by the fuse box. This one looks factory because it is part of the factory bundle that goes through the firewall by the fuse box. Did GM ever use a YEL & PPL/WHT twisted pair for the VSS? Or, is it for something else?
Thank you,
Tim.

 

[df2x4]

I don't know the answer to your question, but the GM factory wiring manual for 1993 trucks might have some useful info. You can download it here in PDF form for free.

https://www.gmt400.com/threads/88-98-service-manuals.43575/

Welcome to the forum!

 

[PlayingWithTBI]

Did GM ever use a YEL & PPL/WHT twisted pair for the VSS?

Yes, that's the connector that goes to the VSS in the tail housing of the trans.

 

[Tim Bro]

Thank you for the welcome.
I have the GM factory wiring manual for 1993 trucks and the Chilton/Haynes manual.
Cant' find the answer.

 

[Tim Bro]

Yes, that's the connector that goes to the VSS in the tail housing of the trans.

Good chance then, that the LT GRN/BLK & PPL/WHT twisted pair were added for a previous engine swap?
Odd though. All of the manuals say that the factory colors are LT GRN/BLK & PPL/WHT.
Nowhere does any manual reference a YEL & PPL/WHT twisted pair.
Thanks,
Tim.

 

[PlayingWithTBI]

Good chance then, that the LT GRN/BLK & PPL/WHT twisted pair were added for a previous engine swap?

Can't help you there, sorry.

 

[Tim Bro]

Can't help you there, sorry.

Does anyone else have a 92-94 with a YEL & PPL/WHT twisted pair coming from their VSS? All of the manuals say LT GRN/BLK & PPL/WHT.

 

[revmatcher]

Not sure if it helps, but on my 1997 the computer performs the functions of the VSSB. As I understand it, VSS signal is analog pulses from the rotating assembly. This is converted and sent in various format to the Speedometer, Cruise Control Module, ABS module, Radio, and even to the Power Steering Module. On my truck PPL/WHT is the (+) from the VSS device at the transmission to the computer. VSS (-) is LT GRN/BLK. YLW is the Crank Sensor Signal CKP from the sensor to the Vehicle Control Module.

 

[eran tomer]

Not sure if it helps, but on my 1997 the computer performs the functions of the VSSB. As I understand it, VSS signal is analog pulses from the rotating assembly. This is converted and sent in various format to the Speedometer, Cruise Control Module, ABS module, Radio, and even to the Power Steering Module. On my truck PPL/WHT is the (+) from the VSS device at the transmission to the computer. VSS (-) is LT GRN/BLK. YLW is the Crank Sensor Signal CKP from the sensor to the Vehicle Control Module.

can you check which wire is connected to which pin in your VSS? I have to put there a new plug and don't know which way to wire it, if it matters at all.

 

[AK49BWL]

I don't think it matters, but pin A is green/black, B purple/white.