where can I find schematic for a Tao Tao ATA 150B?
I am trying to figure out which way the engine fan goes on?
I bought a used one and I am finding a lot of issues.

 

150cc tao tao's are GY6 engines I'm pretty sure. There is no fan other than the one driven by the crankshaft via the flywheel.

Since you're asking for schematics I assume you are referring to an electrically driven fan. 250cc perhaps? Liquid cooled?