Preheating spins

Hello, everybody.

This morning, my preheater acknowledged its service...
The 10A fuse always burns.
This is the fuse for the heater itself (according to circuit diagram 35.1)
There are three fuses in the back of the trunk:
S66 (25A), S62(10A) and S23 (20A)
S62 always burns.
I noticed this by the fact that the display in the driver's door no longer worked, no time was displayed and the heater could not be operated anymore.
I swapped the fuse, and then I tracked what happens.
First things go as usual. You can hear the cracking of the gas pump. It'll take a while. Then it'll stop for a second. Starts again and after some time, when the heater normally ignites and you hear the whirring, then you can see a little smoke from the exhaust of the heater, but at that very moment the fuse burns through.
According to the circuit diagram, S62's supply goes directly to the flame monitor.

Any of you know any advice?

Greetings
Martin