My blower motor ground is cut and tied directly into a ground on the firewall. The not factory setup doesn't work but I cannot find where exactly it should be grounded to. If I stick a wire from the negative side of the battery onto the tab for the ground wire on the blower motor it works so it's gotta be that right?

 

If it doesn't work with a chassis ground, but works by going directly to the battery you've got a bigger problem. Check your motor to chassis ground, because just the weenie wire from the battery isn't gonna cut it.

 

That grounding point you mentioned any good?
edit: I mean ^ditto^