So totally baffled. I noticed this once this summer while tripping to the cabin 250 miles. A line leading to the heat shield wall(or whatever its called) which then leads to the engine and appears to contain coolant, is leaking. The odd thing is it only leaks when i turn the AC on to high or Mid level. For sure high as I have checked. While on the trip i went through 1/3 a can of coolant topping the system off before noticing the High level was triggering this. I am baffled because there should be ZERO reason these two system are reacting. WTF!?. Any insight is welcomed.

Maybe you mean the heater control valve? It will open whenever you set the temperature to warmer temp

Hm. Would explain everything. My blower fan is out anyway so I rarely use the vents.

The heater control valve does not control the vents, it controls how much coolant is allowed to enter the heater core, so that warm air can be allowed to enter the cabin

Ya just thinking aloud. I don't engage the climate control so for now it is no biggie

I wonder whether that would cause the blower to not engage. I have the AC at 60 and that happens. Plus the blower turned on once when I went through a car wash. Odd

^The car automatically turns the climate control system on to rid the air of moisture sometimes.

Well at least my blower works that's all I know. Just gotta find the faulty line or switch for the damn thing now from the climate control.