Are you sure the brake switch didn't fail again? I don't remember off hand which wire it is, but the power goes from the pcm through the brake switch to the servo. At least on my 99. There's actually two power wires at the switch for the cruise. I just looked at the diagram for my 99, and the yellow/red wire should be hot all the time, and the dark blue/red wire will only be hot when the brake isn't pressed. The dark blue/red wire goes to the servo. If your cruise works and that wire shows power, then the next time it quits working check that wire again and that will tell you. Also check the other power wire to make sure it's hot. If it isn't your problem is between the switch and the pcm. If all that checks out good, then it could be a bad ground, or a sensor that's causing the pcm to turn the cruise off, your clockspring, the switches, or a wiring problem in between. Does your cruise light on the dash turn off when it quits working?

 

i read on another site that a vacuum line under the batt. gets corroded and needs to be replaced, i have a similar problem-light on dash comes on-upon start up then i never see it again. but from what the other site said, that was the key, to the problem.

 

I think that's only for Rams. I don't know of any vacuum lines that go under the battery on a Dakota.

 

No vacuum on dak's But same thing happened to our 04 jeep grand cherokee.