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
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.
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!
