Heater control question

blown motor · September 20, 2024, 03:35:24 PM

How many inches of vacuum is there supposed to be on the vacuum supply line that goes from the carb to the heater control? I have 14 but my heater controls don't work right.
74 Challenger.

MoparLeo · September 21, 2024, 02:36:22 PM

The heater control draws vacuum from a fitting on the back of the intake manifold, not the carb
https://themoparshop.com/shop/1-8-1-4-auxiliary-port-pb-vacuum-hose-fitting/

Bullitt- · September 21, 2024, 04:02:34 PM

in my '73 service manual they say 8-inches of vacuum to test operation of the A/C controls and shouldn't drop more than 3/4 of an inch when a function is selected but should return to 8-inches.

MoparLeo · September 21, 2024, 07:54:01 PM

Link to MYMOPAR service manual downloads.
https://mymopar.com/service-manuals/

blown motor · September 22, 2024, 07:23:22 AM

Quote from: MoparLeo on September 21, 2024, 02:36:22 PMThe heater control draws vacuum from a fitting on the back of the intake manifold, not the carb
https://themoparshop.com/shop/1-8-1-4-auxiliary-port-pb-vacuum-hose-fitting/

Yes you're correct. My slip up.

MoparLeo · September 22, 2024, 06:10:55 PM

The link is good for service manuals. Lots of good info.
I am glad you got it figured out.

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