Hot air blows when motor is under strain
Anytime the motor on my truck is under
strain- climbing a hill, "punching" the
accelerator- hot air starts coming out of the
vents. This happens when I just have the
vent blowing or even when the ac is on.
Sometimes letting off the accelerator will
make it go back to cool and other times
you have to turn the blower completely off
for a minute and then turn it back on to get
the cool air to blow again. Engine is 5.3L
V8. Any ideas on what would cause this?