back up lights

[rangermike5353]

i just replaced the back up light switch on the transmission and still no lights. I have checked the power to the plug and its fine. I was replacing the speed sensors on the tranny and rear diff about the same time the lights quit working . Coincidence? Any Help Thx Mike

 

[RonD]

Assume manual trans since you said backup light switch not NSS

There should be power at the switch only when key is on.
Then power on the other wire on the switch when key is on and trans is in reverse, if no power on the other wire then switch is not closing, remove switch and try closing it manually.

If there is power on the other wire in reverse then could be wire to back of truck got damaged OR Ground for the backup lights isn't connected.
You could remove a backup light bulb and test for voltage and Ground(ohm meter) at that end to narrow down search.

 

[rangermike5353]

Is it possible that something in the transmission isnt depressing the switch. i checked the tail lights for power absolutly nothing . ran ohm test and nothing. My next thought is to replace the plug to the switch but i havent been able to locate a harness . So both wires on the plug should be hot while the KO and in reverse? thx Mike

 

[RonD]

Yes, that switch passes power to backup lights, so you could put a jumper wire in that connector to test if lights come on with the Key on