One time last night after turning off the truck the brake lights stayed on. Banged on the pedal several times and tried the park brake and the lights finally went off. When I got home and turned off the truck the brake lights would come on then fade off only to come back on again and repeat. Saw some posts regarding the Rear Wheel Speed sensor but those issues all look to happen when the truck is running, not off.One day two weeks ago when the tach did not work when driving the truck but worked the next time I drove it. Related? Thanks for any comments.

 

It sounds like you have a short. It's odd that it's coming on when turned off.