[Hutch]

hammered68
Sounds as if the High Speed is working
That is great because it verifies a lot of the components are good like the Blower\Fan\Switch\Relay etc.
The blower should be switched off with the ignition
It sounds as if you have a bad ground somewhere in the circuit that takes a while to bleed off. Maybe the engine ground strap?
I am unsure if the fuse and hot wire location you are using is correct on the fuse panel