98 Durango with electrical problems

The first problem to manifest was ABS brakes chattering while driving; sometimes the light would come on, and sometimes it wouldn't. The "code" claimed the problem was the rear differential sensor, which I replaced -- did not fix the problem. Next the speedometer periodically swings wildly, and it looses power (stutters) for a few seconds. Finally, the security system is now acting up. The horn started honking for no reason while parked in the garage, and would not shut off even when the key was inserted and the car started. After 5 minutes it shut off on its own, just when I found the right-sized wrench to remove the battery cable. I've cleaned the battery cables, re-charged the battery, and checked all connectors. Any other ideas???? (112K miles on the vehicle)

just a guess, check the ground from the battery to the truck.........