No reverse lights

[99GreenCummins]

Alright, I was backing our trailer into the barn the other day and my brother told me I didn't have any reverse lights on. I have a 6 spd in my 99. I have gone through all of my lights and they are still all good. I still need to check my grounds but haven't had time to crawl under the truck yet. Any one have any other ideas on what may be causing my lights not to work? I know they were working just a couple weeks ago.

 

[OrangeNV]

check the plug to the reverse switch on the tranny........clean the connection, make sure the wires arent pinched or broke