fbnwest, if you have a 3 spd manual tranny, your stock rev light switch is column mounted, under the hood where the shift linkage comes out of the steering column there should be a small bracket with a round hole.
The bracket is adjustable if the switch is still there (many aren't)
Put the truck in rev and loosen the clamp holding the bracket, Adjust the brackets position just until the lights come on. Tighten clamp, you're good to go.
If the switch is there and appears to be adjusted correctly, you can test this circuit simply by jumping the two wires with the key on. If the rev lights come on, you just need to replace the switch.
If you have a floor shifter, thats a whole other ball of wax...
