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Hi guys. I’m restoring a 1971 Cutlass S with a 455. I have the ball style canister. There is a smaller hose that runs from the canister and is fed through the fire wall and just hanging next to the pedals. Does anyone know where this smaller hose is supposed to plug in to? I can’t figure it out to save my life. Thanks! The smaller diameter hose on the bottom is the one in question. This hose I’m holding is fed through the firewall and dangling.
That hose provides vacuum to the heater/A/C controls. The setup will be different depending on whether or not the car has an A/C vs a heat-only panel, but there's one or two little pancake looking disks on the control panel that feed vacuum to various diaphragms. All comes from that hose.
You'll need to cap it off if not using it - it's a pretty big vacuum leak right now.
Awesome. Thanks for the help! This has heat and A/C. My Grandpa said that it hasn’t had A/C in 38 years. When I turn to the controls to heat, it’s not making any noise and I don’t feel air coming out of the vents. So now there’s a whole new problem.
Get a copy of the chassis service manual - they're extremely helpful.
Something probably failed in the A/C and just never got fixed. Bringing A/C back to life can be a challenge.
The system needs vacuum supplied in order to direct air around. With no vacuum all the air will always go to the floor. It also uses vacuum to BLOCK hot water from the heater box when the temp lever is all the way to COOL. So hot water will always be running through the heater core (assuming the hoses are all hooked up).
You should see a whole mess of vacuum hoses coming out the back of the A/C/heater panel. Two of them should be tee'd together near the panel - use the hose in your hand to supply vacuum to the tee which then splits to both controls.
The controls are little swivel discs that direct vacuum. One is connected to the temp lever and controls whether or not water runs through the heater core. The other is attached to the mode lever and controls which dampers are open or closed - vent vs recirc, windshield, dash vents, floor, etc.
If you have nothing happening then there's no power going to the fan or the fan is busted. Replacing the fan is unpleasant, so hopefully not that. Check your ACC fuses first. The LO and two medium speeds run power through the A/C panel (there's a micro switch that's open when the system is OFF) then through the fan switch then out the hole in the firewall to the resistor pack in the A/C box. The HI fan speed is controlled by a relay in the engine compartment and its own fuse. This often has trouble and gets hacked up over the years.
December 29th, 2022, 11:45 PM
