handymanmac,
It sounds like you have a bad connection between the battery and the system. Are the cables clean and tight? The point is, if the little blower motor is making the difference between having enough oink to start or not to start, something is terribly wrong.
A current draw meter should show no more than 250 amps (approx) with your new battery...if it exceeds that, the starter is working much too hard to crank the engine over. This means a bum starter or a binding of some sort in the engine itself.
Your blower motor mystery is actually an indicator of a problem somewhere else....I think!
Stuart
