Hvac vacuum lines?

[PJNJ201]

Hey guys. trying to figure out where certain vacuum lines go from the twinkie style vacuum tank by the blower motor. car is an 84 buick regal.

As pictured below, the line with the red and black braded sleeve that IS connected is a gray line. the nipple on there that has nothing connected, there was a black line that was just laying there tucked away so i took it off for now. Also as pictured, there is a tannish line that is also just hanging there tucked away. Currently all i have is defrost and vent and high speed does not work. Thanks all!

 

[mikester]

On my car theres a purple line coming from the firewall going to the vacuum ball. That might be the gray line on your car just faded. The tan line goes to the valve in the heater hose. Then you will have a line feeding the ball or tank coming from the manifold providing vacuum.

 

[PJNJ201]

On my car theres a purple line coming from the firewall going to the vacuum ball. That might be the gray line on your car just faded. The tan line goes to the valve in the heater hose. Then you will have a line feeding the ball or tank coming from the manifold providing vacuum.
View attachment 195628

Thanks for the info! I dont have a valve in my heater hose 🤔 is there a specific part number? how does it go in there? & also, im out of sources for vacuum. What is best to tee into for the vacuum?

 

[mikester]

Thanks for the info! I dont have a valve in my heater hose 🤔 is there a specific part number? how does it go in there? & also, im out of sources for vacuum. What is best to tee into for the vacuum?

Not sure what ports are on a Buick. The 350 has a threaded hole on the back of the manifold. I put a T in the line going to the trans modulator.

 

[350Regal]

On my car theres a purple line coming from the firewall going to the vacuum ball. That might be the gray line on your car just faded. The tan line goes to the valve in the heater hose. Then you will have a line feeding the ball or tank coming from the manifold providing vacuum.
View attachment 195628

I know this is off topic.. but...damn that engine bay I only see a part of it it looks very nice. Josh

 

[mikester]

I know this is off topic.. but...damn that engine bay I only see a part of it it looks very nice. Josh

Thanks for the compliment. Heres a better picture. Its my 83 Malibu wagon.

 

[PJNJ201]

Thanks for the compliment. Heres a better picture. Its my 83 Malibu wagon.

View attachment 195678 I ordered an AC Delco Heater valve and i will also tee the line into the trans modulator line. Thanks again for the help! And i agree with above, looks super clean in there!

 

[mikester]

Glad it helped. Let us know if it all works out.

 

[57 Handyman]

PJNJ, the fan speed issue is probably caused by a bad fan resistor which sits on top of AC box. With regard to the vacuum lines and breadbox tank, there probably IS a leak that prevents the HVAC actuator from directing airflow between floor and defrost. The box in my 87 El Camino leaked so I replaced it with a small vacuum ball that is more readily available than the box. I suggest either borrowing a vacuum test kit from Autozone or purchasing one from Amazon. I opted to purchase one since it was around $25 or so and a great addition to my hobbyist toolbox. The vac pump tester is very helpful and key in troubleshooting your HVAC actuators, dash controls, plastic lines, etc.

 

[ELCAM]

Hi speed is powered by the Hi speed relay all the lower speeds are powered through the resistor block. Make sure the orange wire from the HVAC controll has 12V present at the relay when the switch is in the hi setting.

Make sure there is 12V on the red 12Ga wire going into the relay.

If 12V is present in both cases the relay is defective.