Slight amount of heat all the time, is it normal?

[2x_Tom]

When I drive it seems like hot air is coming out of my floor vents. Not very much of it and the fan isn't on. It's a 71 non-AC truck. Is that normal?

The heater core is also hot all the time. Should there be some sort of valve that keeps water from flowing through it with the heat off?

[LockDoc]

Originally Posted by 2x_Tom

When I drive it seems like hot air is coming out of my floor vents. Not very much of it and the fan isn't on. It's a 71 non-AC truck. Is that normal?

The heater core is also hot all the time. Should there be some sort of valve that keeps water from flowing through it with the heat off?

Normally no valve on the heater hoses but people have added them to some trucks over the years. I would bet you have a mouse nest in your heater box that is keeping the flapper from closing all the way and allowing the hot air in, or the rubber seal on the flapper is bad with the same results....

LockDoc

[2x_Tom]

Thanks for the advice. I will check in there to see what's going on.

[LockDoc]

Originally Posted by 2x_Tom

Thanks for the advice. I will check in there to see what's going on.

Here is a pretty good thread on the subject. It is an older thread but the procedure is still the same....

http://67-72chevytrucks.com/vboard/s...d.php?t=370525

You pretty much have to read the whole thread. There is a link to an FAQ on the procedure in that thread also.

LockDoc