Does the coolant system have any control or.

Does the coolant system have any control or influence on the electrical control system for the cabin heat/blower motor?

The defrost on the car has not been working well, which led me to suspect a minor leak in my heater core. I tried adding Bars Leak for heater cores to my cooling system and the blower motor quit working after I guess the first time running the car. I am thinking it is coincidental?

Any way, I have connected the blower straight to the battery to eliminate that as the issue.

I have now replaced the resistor and the heater control unit. Still no blower.

The fuses have continuity.

The relay works, however, is not being energized.

Thanks for your help.
Josh