Seat adjustment back no longer moves forward, back

Hello.

Unfortunately, my seat adjustment on the passenger side suddenly no longer works at the back.
Down there is still -- but no more going forward and back.
The engine moves very easily. But nothing seems to block (with the hand crank it is easy)
Could I have loosened, damaged anything in the course of battery measurement? (there was no short)
...or could the yellow relay just have broken?

And my flasher has evolved into a warning flashing system
Here again, assume corrosion in the plug or. The lamp holder..

greetings