[SilverS8]

Gently wiggle out the circuit board, by pushing carefully on the connectors it almost falls out.

I immediatly saw the difference on the circuit boards and no wonder the L unit wasn't a straight swap.

Since my pump surely had some electrical difficulties i opened up the cover of the pump/motor (Three screws ) carefully lifted the lid and did quickly see what caused all the fuss.. The plate that moves around was shed to pieces, most likely stopping the motor from turning and therefor causing the fuses to go bye-bye.