The low air brake buzzer,and light are coming on with key out. Replaced panel and both relays behind dash no change 02 peterbilt 379 any thoughts?
Check down by your clutch pedal. There is a little door with breakers and relays. Mine got wet because of a windshield water leak. Caused my cab clearance lights to come on with the switch off. Could be it..don't know. I see this post was Wednesday so you may have diagnosed it already?
