1998 Pontiac Montana Power door and power seat

I need a bit more info if you would. You say power door problems. Does this have a power window and door lock? Which is not working the door lock, the window or both? On the seat has the seat motors ever been wet? I have a Bravada with power seats that I bought to sell and it had a soda explode under the seat shorting out the motors. If you would look under the seat and see if any of the wiring looks like the plastic is melted. Get back to me and I will see what we can figure out from there.

It is the power sliding door on the passenger side of the van that does not open. With three motors under the seat, what is the possibilities of all three being shorted? I looked under the seat and do not see anything that is melted. The power door locks work fine, nut the door will not open on its own

Ok so if I understand you correctly the sliding door will not open on its own power? You can open it manually right? As for the seat I wouldn't think that the motors would all go bad. The three motors are one for lumbar and one for up and down and one for forward and back. Now do you have a voltmeter one that is battery operated? Let me know and we will go from there. Is a couple of tests I need you to be able to do that will require the voltmeter. So get back to me and we will go from there.

I have a voltmeter. I checked, and there is power going to the seat.

Ok if you have power going to the seat then it is either the motors which I doubt or its the switch. I would check the switch first.