Topic: Have some heater/ climate controls issues

[Jhensche@hotmail.com]

I have a1979 TA K Code
6.6l

The issue I'm having is that after replacing the control head, (new one) I'm not getting any airflow to the defroster or vents only the lower heater. Also I'm not getting the telltale hiss as the selector lever is moved. I'm thinking no vacuum to the system??? Any idea where the vacuum source line would be inside the engine compartment and where it attaches. Other ideas?

[Wallington]

Yes, sounds like you have no vacuum line to the heater controls. There are two vacuum ports on the 403 intake, one at the front for emissions, one at the rear behind the carb that runs to the heater controls. It will also have a one-way check-valve on it that can also fail or leak but you'd at least have something even if it was faulty,would just drop to other settings and open air doors when vacuum dropped too much.

[Wallington]

In this pic you can only just make out the black vacuum line heading from behind the carb to the upper left with black checkvalve mid-way, passing over the brass heater connection in the intake into the firewall grommet.

[Jhensche@hotmail.com]

Thank you for the insightful assistance. And the last picture is golden. Thankyou