Bob Rentfro wrote:
I'm still...well, always, troubleshooting my HVAC and now there is a new
twist. After driving for about 15 minutes with nothing on HVAC wise, I can
start to feel a little wicked hot air at my feet and out of the center vents
(thermometer in center vent reads 110 degrees) but it's just "seeping" out.
I think it has lost it's mind.
Any ideas?
The way the "wonderful" Type II system is actually wired up the control
system doesn't actually know if it is supposed to be "on" or "off." The
on/off of the system is a completely separate circuit, which is
controlled by vacuum from the push button assembly. What that means is
that even when your system is "off" it is still trying to heat/cool your
car (just with no blower).
What it sounds like is the system determined there was a need for heat
and was allowing hot water through the heater core even though the
system is "off." The assumption by MB is that when the blower is off
there will be no airflow so it doesn't really matter if the system is
left on, but in your case some airflow is occuring and causing the
"seep." Unfortunately, that is "proper" operation of the system from
my understanding of it.
If anything, you might want to check and make sure that the
recirculation flap is properly closing as thats the only thing I know of
that would cause airflow. FWIW it happens in my car as well... just
never been bad enough to crawl around underneath the blower though!
Best of luck with it,
John
'79 300SD
