My 93 pickup keeps frying the reverse light switch. Gone through two switches and I'm not about to buy a third one until I figure this out. The switches last about 2-3 weeks then seem to melt between the terminals. Lights work fine with a jumper wire in the switch plug. I have not left the jumper wire in any longer than one minute, jumper does not seem to get hot. Harness between tail lights and cab look fine. All fuses are good. Bulbs good. Plug is clean. Only other electrical issue with the truck is the vehicle speed sensor does not work but sometimes the speedometer jumps all over the board, rolling or not. I'm not sure if the reverse light switch and the vss issues are related. Any input or ideas would be appreciated. Thanks!

 

Just what brand switches are you buying ??

If the circuit protection does not open you don`t have a short.

If the circuit was open the lights would not work.

Your just using the stock back up lights ??

Now both the back up lights and the speed sensor are powered via the 10 amp gauge fuse. Has this fuse been replaced with a higher amperage fuse??

If the speed sensor was shorted to the transmission the gauge fuse should open.

By chance are your back up lights staying on all the time causing the switch to get hot and melt??