Have a look at the main contactor in the electrical panel in the back.

Remove the inspection covers & you will see it.

Ive changed a couple of these contactors on Traigo 48s over the years.

If you unscrew the contactor to remove it, make sure you don't loose the clear plastic insulator sheet mounted behind it.

Also check the blade fuses in the black fuse holders, ive had the terminals in the fuse holders on older / high hours Traigo 48 spread slightly causing odd electrical faults over bumps.