Community Forums

2TALK42 · 01-31-2012, 10:34 AM

Replaced heater core, now cannot make air blow out of reg ac vents. When I turn ac on and put on dash vents I can hear a buzzing noise in dash and ac will only come out of floor or defrost vents...just a little bit confused...anybody else ever saw this?

Algoma · 01-31-2012, 12:32 PM

That buzzing is the vacuum pump that operates the dash vents. You probably knocked off the air line from the pump when playing with the heater core. It is a thin black hose that goes from the pump to an accumulator that you can get to when you put the generator slide out.

2TALK42 · 01-31-2012, 01:46 PM

Repair has been made...loose vacuum line under dash inside. THANK YOU!!!

takepride · 02-03-2012, 08:44 PM

Though not exactly your issue, I just had to replace the water valve that turns off the flow to the dash heater core when trying to run dash AC. Between the two, the air was coming out warm-ish. Hopefully this will help someone in their diagnosis. Part was $147 (which seemed high).

Cookiejar · 03-09-2012, 06:38 PM

I have a similar problem with my dash A/C. Where did you get water valve that turns off the flow to the dash heater core and do you have a part number?

Cookiejar
2007 Alpine 40 FDTS

Dave Fernandez · 03-10-2012, 10:56 AM

If you are not getting heat through the A/C Dash Vents check the defroster vents to see if you are getting heat through them. If not than check the Vacuum Pump and hose connections to make sure they are not loosing vacuum. You may also check the dash controls and vacuum motors to see if they are connected and working.

If you are not getting any heat from the defroster vents you can take the heater control valve to your local parts store to see if they have a replacement. Paul Sullivan found Thermotion Corp, as a supplier for the heater control “H” valve.

Thermotion

Paul "Sully" Sullivan · 03-10-2012, 12:24 PM

If it is the H valve that you are looking for, they are available from
Thermotion in Ohio. They have the valve and the motor,
but the motor needs an extra rheostat to make it graduate rathe than
just on and off.

I have an extra H valve, if you just need that.

Cookiejar · 03-11-2012, 05:02 AM

Thanks Dave & Paul. When the dash air is heating, is blows heat out of the dash, floor, defroster, appropriate to the selector. Same when cooling. However, the heat or cool air only lasts for 15 to 30 minutes. Vacuum portion seems to be working properly. Still working on a solution.