Lima's not charging anymore! Generator od. Regulators?

Hello for now!

I have the following problem with my 92 ABH:

I recently changed the thermostat! I'm not sure. 2l of cooling water over the belt! Since then I have a constant squeaking in the engine compartment, as if the V-belt is defective!

Now my battery is constantly unloading!

I charged the battery 20h, then had successful 14V!

==References====External links== 20km travel again voltage measured:
At rest 12V
With running engine only 11,6V

Was kann da nun defekt sein?
A coincidence, or does that have anything to do with the fact that the cooling water has sunken over the belt?
More like Lima or Lima controls?

Thank you for now!

grolly