There are likely several sources of problems. How'* the battery? Are the terminals clean in between the two positive connectors. There'* a lead insert between them: is the corrosion in between that'* affective the power level when the seat draws a high current?
But the first thing I thought of was my 93. It had a problem with the auto locks going off and then working again after minutes or letting the car sit. The AC control panel also defaulted to defrost and the AC compressor turned on along with the engine cooling fans that come on with the AC compressor.
I decided it was the buss for the grounds. The driver'* side has one and the passenger side has one. If you're in a climate where there'* snow, rain, salt, carried in onto the carpet that keeps that area wet, corrosion may be on the buss.
It would take some circuit checking in the Factory Service Manual to see if the power seat and the locks share a ground. But you might try compressing (hitting) that buss connection area with your foot to see if there'* any effect. It doesn't look too hard to get at to check either.