FOUND IT!

It was the OVP Relay. So add that to the list of commonly listed options that can be the culprit. Took a bit of searching on here, but what tipped me off after rechecking, was a post that mentioned the ABS light and no Tach, in relation to the OVP.

So, low-and-behold, checked the OVP as well, it was blown. Klima is actually working with only 1 fully operational relay. (The second relay was missing one of two contacts and won't disconnect all the time, its also discolored and burnt compared to the operational relay.)

All that aside, it looks like a pretty simple circuitboard. If someone could replicate the board, I can solder everything together. (I don't have a print station.) Anyway, thanks all. This is a great board.