Gauges start reading after truck is off. Garage replaced ignition switch. But that didn’t help. I have killed one battery and it has been draining the new battery.

 

Something is allowing power to your gauges. As a quick cheap fix you could install one of those cut off switches on the battery until the problem is solved. Sometimes alternators have been the culprit.

 

THANKS! Oilcanhenry that’s a great temporary fix. The alternator checked out ok. Thanks again.

 

2 suggestions-determine which fuse is controlling the circuit by removing fuses until the circuit is opened, if you can isolate the circuit look for shorts in that section of wiring. A simple "idiot light" current test probe can help you identify the wires carrying current to isolate the bad wiring.