I am working on an 85 euro with the s4 seats. The driver backrest only moves about an inch either way. It's NOT the switch as I have tried two of them and the one I just installed is brand new. All other positions work fine. It almost feels like it's jammed. Does anyone have suggestions? The seats are out of the car so I can access underneath easily.

Thanks for any help!!!

 

Can you tell if the motor is still trying to turn?

One way to tell would be sound (can you hear it)?
Another would be power draw. If it was in the car, you could see lights dimming or the volt meter going down as the motor stalled & drew more power.

When I test stuff 'on the bench' like this, I use a battery charger as a power source. Mine has a meter on it, so I can see how much power is being drawn. That would be a good way to check, if you power it that way.

If the motor is drawing power, I think your guess that 'it's jammed' would be correct. Unfortunately, the motor is buried way up in the seat back. Getting to it is not trivial. The gears are lower, but still inside the seat back. The PET shows where the motor and gears are hidden.