I was once inside a customer's glove box. Can't remember if I was after a wheel lock key or Cabin Filter. It was a dimly lit corner of the shop, but I was just removing piles of God only knows what withy bare hands. No need for paying attention. WARNING: SQUEAMISH PEOPLE STOP READING NOW... I stuck my hand into that glove box for another fresh fistful of goodies when I felt something mushy, gooey, wet, and warm. Just as a casual "WTF" was coming out of my mouth, I opened my hand to find a fresh used tampon! Needless to say, I barfed all over the interior of that particular vehicle. To make a long story short, the lady who owned the vehicle refused to be told in private about what had happened. She wanted the crowded waiting area to hear exactly how we had screwed up her car. I wasn't allowed to be there when she found out, but my service manager at the time told me that he explained everything to her and didn't stop when she became embarrassed. That's the worst thing I've ever found in a customer's car. I've seen all the usual: Dead critters, pets, The police dog that scared me half to death because I didn't know he was sitting in the back, porn, weapons, drugs, sex toys, wads of cash, Social Security Cards, tons of things that would enable identity theft, the list goes on. But that damn "Lady's cork" was by far the worst thing I've ever found. If I'm lying, I'm dying...
Also of note, there is a TSB for this particular forward/backward but it is for the recliner position so may not apply to you. Check it out, may help you pin it down. If I understand correctly, you are having trouble but it is intermittent. I would first start by checking any loose connections, often stuff rolls under the seat, dislocates something. You could throw a switch at it and not get joy and still have that intermittent.
I would wiggle test harness first with said switch in operation, you will probably find that it is not the switch, but just a loose contact.
I know that most times when I get a problem like that, I find a toy, old coffee mug, or even worse, women's underpants jamming up something. If you get my drift.
One of the grossest things I found shorting out a seat motor, a rotten sandwich once, another time, a rotten apple. Both times, just the juice from the fermenting, offending food was enough to seep in the connections and short intermittent.
And the worst most disgusting thing that you will not believe, a used condom somehow got in the cracks. Wrapped itself around a motor shaft. I went in the waiting area and dangled the now unrolled condom in front of the client. I said, really? You almost just paid for seat cleaning cuz I actually just gagged and threw up in my mouth when I found this. Your car is now fixed.
The other clients in the waiting area freaked. Safe to say, I never saw that client again. Disgusting is a understatement.
No offense to women, but they have the craziest things lying around here and there that will gross out even the most hardened mechanic. I once had to adjust a parking brake lever, had to go under the center console for that. Guess what I found, a god damn used sanitary napkin for you know what. That also was another gag moment. So my half assed brain put on double gloves, and I threw that right in the center of her dash board and parked the car. I then gave her the keys, winked, and said you need to check you tpms system, the light is flashing.
I think the car skidded in reverse so fast she left the lot. LMAO.
That is what 27yrs in this trade get you. But I think plumbers actually have the grossest job.