Back up lights not working

[swes64]

have a 06 2500 4x4 diesel. My back up lights stopped working. Bulbs are good, there's no power at the bub end. The other lights work. After some searching I replaced the neutral safety switch. Still no backup lights. Furthermore After replacing the neutral safety switch the 2nd gear, drive and neutral indicators temporally light up then go out. If I move the shifter and hold it the lights come on.
Well after spending too much time adjusting the shift cable in order to get the corresponding lights to light up on the gear indicator without success I put the old neutral safety switch back in even though seeped very smalll amount of AT fluid. Everything went back to normal except the backup lights do not work. Any thoughts before I take it to a shop.
Thanks.

 

[3pedals]

On my half ton was a chafed wire running along DS frame rail under bed. Drove like that for a couple years, until fuel pump was cutting out. Pulled bed to replace fuel pump and saw the problem.

 

[swes64]

Thanks I'll look it to that. I Need to figure out the wire color that comes out out of the TIPM as I did for the left left turn signal. I believe the TIPM is bad.