E89 blowing 20 amp hardtop control fuse

[Davidion]

Has anyone had experience of the main roof operation 20amp fuse blowing? My Z e89 has been with the dealer for 3 weeks, warranty thank god , but they can't find the cause. They have replaced the hydraulic motor unit, hardtop controller, 2 roof relays and 2 boot micro switches.
I have collected the repaired car twice in that three weeks only to drive it straight back with the same fuse blown. Leaves you without roof or boot operation.
Thankfully not happened in the rain yet.
Missing the best of summer weather in Z4.

 

[Nictrix]

Sounds like it will be a wiring fault rather than a sensor or relay

 

[Maniac]

Sounds like it will be a wiring fault rather than a sensor or relay

Ditto. I'm going to say it's a short.

 

[Davidion]

As most heavy current components have been replaced the "short" is all thats really left.
Just thought maybe there is a known pinch point somewhere that someone has seen happen before.
There is no prescribed timescale under warranty that a dealer can have to repair a fault.
Obtained from the Motor Ombudsmen this morning. So frustrating.