86 Daytona--no heat!

[Backally Bob]

Heater was working fine, but suddenly got zero heat from it. I
recently replaced a couple bulbs in the heater/air conditional
controls but not sure if this problem started before or after I
replaced the bulbs. I traced the problem to a vacuum valve in the
hoses running to the heat exchanger. If I unplug the (grey)vacuum
line, the valve opens letting water to the heat exchanger and I get
lots of heat. Problem is there always seems to be vacuum at that line
so the valve stays closed. Can anyone tell me what regulates the
vacuum in that line, and will I hurt anything by just capping it? (My
guess is the valve is supposed to close with the air conditioner on to
reduce high temps at the heat exchanger)

86 Dodge Daytona w/2.2 turbo.

Thanks in advance for any help, e-mail me would be great.

Backally Bob
[email protected]

 

[Marvin Cohen]

Valve is controlled by the recirc feature (max a/c). Perhaps the switch is
screwed up inside the hvac head unit or its sticking. Also be sure there
has been no custom rerouting of any vacuum lines under the dash.

 

[Backally Bob]

Thanks for the help...switch on the hvac was stuck. Was stuck down so
it just looked like a plastic support, but working the heat control
made me figure it should be doing something. Replaced a spring inside
(probably popped out when I was changing the switch lightbulbs) and it
works fine.
Thanks again, windows don't fog up now with heater on at zero F
outside!