Air conditioner and heater only working on one side?

BUICK_DUDE

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91 POSTS

There is vacuum to the valve, but no hose goes to the firewall. So I need to find that vacuum. I'm going to keep looking. The valve does work.

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Monday, March 22nd, 2021 AT 2:17 PM (Merged)

JACOBANDNICKOLAS

MECHANIC
109,874 POSTS

Hi,

Yes, if you follow the supply hose from behind the controller, it should lead you to where it is coming into the vehicle. All you need to do is run a new line to it if needed. Take vacuum right from the intake manifold.

Let me know if I can help.

Joe

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Monday, March 22nd, 2021 AT 2:17 PM (Merged)

BUICK_DUDE

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How can I find out which line is the supply hose?

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Monday, March 22nd, 2021 AT 2:17 PM (Merged)

JACOBANDNICKOLAS

MECHANIC
109,874 POSTS

Hi,

Take a look at the attached pic. Let me know if that is what you needed.

Joe

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Monday, March 22nd, 2021 AT 2:17 PM (Merged)

BUICK_DUDE

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91 POSTS

Turns out the engine vacuum line was plugged into the vacuum box port and the second port did not connect to the violet line. Bypassed the airbox (for now) and connected the engine vacuum directly to the violet vacuum line and the A/C blew from the dash vents!

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Monday, March 22nd, 2021 AT 2:17 PM (Merged)

JACOBANDNICKOLAS

MECHANIC
109,874 POSTS

Hi,

That is certainly the problem. I'm glad you found it and got things working. Please feel free to come back in the future if you have questions.

Take care,
Joe

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Monday, March 22nd, 2021 AT 2:17 PM (Merged)

BUICK_DUDE