Hot tub is an older Jacuzzi from mid-90's - Jacuzzi platinum series, lexus plus model.

The GFI trips as soon as I switch it to the on position. Per the suggestions on this board, I diagnosed that it is the blower. I replaced the blower with a brand new model. Same result, gfi trips immediately. Blower is 110V 1hp. So the problem is not the blower itself.

More backstory - It appears as though a mouse built a nest in the control box this past winter, and chewed through the insulation on the hot and neutral wires that lead to the blower. I don't know for certain, but suspect, that these two wires shorted at some point. So, I'm thinking that the problem was never the blower itself, but maybe in the control box circuitry of the tub. Perhaps the short damaged a component on the main board?

Without the blower motor attached, the remainder of the tub appears to work flawlessly.

Any ideas? How can I go about troubleshooting the problem on the main circuit board? Anyone know where I can find a schematic for a tub this old?