Well, I never did pay attention to the warning about the auxiliary water pump.

After finishing five months of work on the SD, it turns out that the blower does not function. After some meticulous checking, the controller is fine, the blower itself is fine and the resistors are fine. The only thing remaining is the CCU.

Remove CCU and pull the bottom plate to find some overheating within the unit. Not a good sign.

Replaced CCU and blower operates normally. But, I only run it for about 30 seconds.

I recall the caveat about the auxiliary water pump. I remove the pump and apply 12V to it from a battery while observing an ammeter. No rotation on the pump and 2.5A draw on the ammeter.

Replace pump and system operates normally.

So, a word to the wise:

Install a 1 amp fuse in the 12V supply to the aux. water pump. Someday it will save you the cost of a CCU. Wish I did,