Speedo not working

[Wkndrcr]

Hi all, new guy here. I was looking for some help on fixing my speedo in my 1989 Silverado, with a 700r4, 4x4. I didnt see an electrical section anywhere, and figured it might be condidered trans related.

Mods, please move if its in the wrong area.

Anyway my speedo wont work, its electrical. It is plugged in!!! I have swapped out the tranny and case due to slipping issues. It didnt work before or after the swap. I have also swapped out the instrument cluster, and still its not working.

Anyone got any ideas??? On the plug on the transfer case, is there suppose to be any volts in or out? Or restiance? and how much either way? Anyone?

[357mag]

Check the VSS on the tailshaft. You should see 800-2200 or so ohms when it's out of the truck. I just replaced mine, although my speedo worked, but the needle was all over the gauge. Does your cruise control work? or the ABS?

Tim sends

[Wkndrcr]

Actually no the cruise dosnt work, but I wasnt worried cause I never use it in other vehicles. As for ABS, dont even know if I have it??? I dont think I do.

What does VSS mean, Vehicle speed sensor Im guessing. Can I just unscrew it from the transfer case?

I assume I should have 12volts coming in to the sensor and the sensor is basicly resistor. And the resistance is controlled by output shaft speed?

And Thank you Tim!!!

Ill be under the truck tommorow to check things out

[Wkndrcr]

Just getting home, I tested the sensor and it had 1500 ohms, its comes out easy!! So the sensor should be fine.

It tested the wires for 12v with the key in the on postion and no power. Trace it back across the top of the transmission and headed up towards the distrubuter area.

Were do they go from here???

They are a purple with white strip and a yellow wire.