Got a new(sort of) problem with my truck. The prior owner told me that sometime it sticks in 4 or 2WD, the speedometer jumps around or goes to zero, and the windshiel wipers turn on/off eratically. I replaced the shift motor on the transfer case and also had the pdp replaced (circuit breaker box under hood). I have basically the same problem but I noticed that all them issues are related. It happens for no reason as far as I know. Usually what happen is I hear a tone and the ABS and brake warning light in on. I try the windshield wipers and they don't work, the speedometer is jumping around or at zero AND the 4WD sero warning is no AND the light on the 2/4 wd select panel flash. All thesse conditions happen at the same time and then stop. I managed to get to work today with NO issues but that is rare. I have tried hitting big bumps to see if something is loose but no joy. I also pulled the codes from you bully dog but it shows none. Any ideas? Other than that this truck is great.