[69chevellesupersport]

I recently installed a vintage air setup in my 69 chevelle. The heat has yet to work correctly. I checked to make sure the heater control valve is opening by unhooking the line from the water pump and blowing through the hose. Water came out of the fitting in the pump while the key was turned on. When I switched to AC mode nothing came through. I do not have the AC lines hooked up yet for the system if that makes any difference. Sometimes when I first cut on the fan it blows hot air for a minute or so then it turns cold.
Any ideas guys?

[fasteddies68]

I hope you are not running this with the compressor dry. I installed a V.A. system on my '68 and it works perfect.

[Philip]

Where do you have the hoses attached? If in the wrong spot you will not have water circulating through the heater core. One needs to be in the intake (pressure feed line) and the other to the water pump or radiator (return points). Attaching to the water pump and radiator gives no flow.

[69chevellesupersport]

No its not running dry I dont have the compressor mounted yet. One line runs to the intake and one to the water pump. If they are hooked up backwards would it affect heating?

[Bryan59EC]

Should not really affect the heating.

Perhaps the valve is not opening all the way.
Might want to check to see that you have power to it and that it is grounded correctly.
I have heard of them failing.
You should be able to hear it open and close by moving the temp lever. (not sure, I will go out and check in a bit)
I also mounted this valve where I could service it easily if needed ----not tucked under the fender where it could not be seen.

My car runs pretty darn cold when the temps outside are low----so it takes a long time to get any heat, and the heat that does come out is not hot-----more of a warmish.
The heater in my pickups will cook you right out.

[oman]

Originally Posted by Philip

Where do you have the hoses attached? If in the wrong spot you will not have water circulating through the heater core. One needs to be in the intake (pressure feed line) and the other to the water pump or radiator (return points). Attaching to the water pump and radiator gives no flow.

One Vintage Air System I had used TWO 5/8 dia. heater hoses. You literally had to swap the 3/4 GM outlet on the engine...I think it was the manifold but it was a while ago, from a 3/4 nipple to a 5/8 nipple and get a 2nd length of 5/ 8 heater hose.

GM used one 3/4 hose and one 5/8. When you get to both lines being 5/8 it seems to me it becomes easy to swap the hoses in such a way that the water can be supplied to the core from the WRONG engine manifold / water pump source. I can't say what is gonna happen when what should be the "suppled" side of the heater core becomes the "outlet" side of the heater core. All I can say for sure is that it is easier to reverse the hoses at the core when they are both the same size at the engine end.

[69chevellesupersport]

I can't hear the valve opening just a click from the relay so maybe it is malfunctioning. My car runs around 170 deg. It is opening some though because I was able to blow pressure through the lines.

[69chevellesupersport]

I fixed the issue by swapping the heater hoses around which for some reason were hooked up backwards. I guess this system must flow one direction in order to heat properly. The line is running from the intake through Hcv to heater core then out to the water pump. Once the engine heats to around 130 it starts to blow warm and by the time 180 comes around it is hot. Works very well compared to the factory single vent under the dash..ha