I have a 84Z28 with air cond. When you are moving down the hwy. is there supposed to be continual air movement from the lower center vents near the console? If I bypass the heater there is cool air. If I run the proper heater hose connection then there is warm air. I assume I am picking up warmth from the heater core. Is this common? It doesnt seem reasonable because of the summer heat and then picking up extra heat from the core.

 

It's normal.. Read here.

https://www.thirdgen.org/techbb2/sho...threadid=41536

 

that's amazing

 

Neat, I never knew about that. Does it stop when you have ac or heat on?

 

Thanks for the info. May add that other valve. I already have the one, but I may put one on the other line. One valve seems to keep the water near the heater core and keeps it warm.