You have one of two choices: 1. A wire shorting out, maybe under the seat. 2. A wire shorting out somewhere else. At least that's been my experience.

I had a Corvette that would randomly tilt the driver's seat up and move it forward. Not pleasant. Sticking my hand under the seat and wiggling the wires would sometimes make a difference. After taking the drivers seat out 5 times I finally gave up and pulled the fuse.

Get a wiring diagram and see if there is a wire common to both seats.

Best of luck