You can bypass the heater matrix which will flood the footwell when the seal fails.
I have seen the two flow/return pipes between bulkhead and exhaust cam cut and then connected together, removing the heater matrix from the circuit.
Been there, done that and still trying to find the time to replace the heater core!
It definately sounds like the blower motor is drawing excessive current.
I would strongly reccomend that you don't run it again until you diagnose the fault as if the fuse has been bypassed or replaced with a piece of metal, and with the description you provide, it sounds likely it has been since it hasn't blown, then you run a strong risk of starting a fire.
Running the fan and hoping it improves is not a good idea as you have no way of telling how hot the wiring is getting and you're also at risk of damaging the alternator as it is being asked to supply current way above it's designed capability.