That motor HAS to require more than 5 amps, 5 amps is around 65 watts (depending on system voltage). 30 seems a bit much (the engine cooling fan is fused at 50 amps, it's a BIG motor) but I can see fusing it at 30 since the fuse rating is essentially calculated to protect the wiring to the motor.

I don't know for sure what "SET" you replaced, I assume the blower "resistor" as well as blower motor. Salvage parts are fine, but don't assume they are 100% good. The circuit is simple (see the service manual) all you have is the control voltage going to the "resistor", and the feed from the fuse, thru the "resistor" on to the motor.