Hi,

Took my '70 240 for a spin last night, and cool air came out the center vent, while the heater was on! I assume there is a adjustment on one of the cables, as the heat came out both the defroster and lower heat vents, but as I drove on the hwy, the cool air came through the center vent.

Any ideas where I should look first?

Thanks in advance!

Bob:squareeye

Actually, it's pretty typical for the center vent to have a slight breeze of cold air, even with the levers turned to blow hot air.

What happens is the center "Flap" has a foam pad that wears out over time. When I changed my heater core, I put some NEW foam around that Flap to minimize the cold air coming in thru the center vent. I'm not sure if the foam can be fixed without removing the side plate that holds the heater core in the large airbox assembly. And unfortunately, removing the side panel includes removing the heater hoses and cables just to start with.

My best suggestion is to stuff some foam into the slots of the center vent. Maybe some 1/4" foam cut to 4" X 12" and slid into the center slot so that the foam ripples up and down like an accordian, blocking the air from freezing your hand when you shift.

That's the best I can do for ya unless you wanna go the hard route and tear the whole thing apart and refoam the "center and side vents Flap"

Dave.

Prior posts that may help:

http://www.classiczcars.com/forums/showthread.php?t=13929

http://www.classiczcars.com/forums/showthread.php?t=1642

E

But you should also verify that the cable that closes the vent flap hasn't come loose from the heater box end. Check to make certain that something is moving when you move the lever from Vent to Heat.