The Stovebolt Site Forums The Shop Area General Truck Talk '72 C-10: NO HEAT !!!!!

This may qualify for the "gremlin dept"....

1972 Chevy C-10 2WD, 250/six, standard heater (no A/C).

Within the last two years (20,000 miles):

New Radiator (proper OEM core)

New Heater Core

New Radiator & Heater hoses

New T-stat (195 Stant)

Rebuilt Water Pump.


Engine comes up to operating temp within 10 minutes and stays there.

Drove to work today (1/2 hour trip), ambient air temp about 15 deg F. Heater blew not quite luke-warm air the whole way.

Got to work, left truck idling, opened hood, felt hoses: both were quite hot; heater still blowing cool/cold?

ANybody know how good the '67-'72 heaters were in the first place ?

(Hoping not to have to pull the heat box again; gotta pull the right-front fender-well to do that... )

Frank ("Freezin' mah toes off!") McMullen

If the hoses going into the heater core are real hot, but the air comming out of the vents isn't very warm, i'd wonder if maybe the heater core dosen't have some kind of dust or crud preventing the air from getting sucked thru it.

You may also want to make sure the duct work going from the blower motor to the vents is solid.. if you have holes or cracks in that ductwork, the warm air passing thru would suck cold air into it, cooling the warm air and giving you luke warm output.

The other thing to check, with this being a newer truck, is the linkage for the hot/cool slider control.. you may have the lever set to 'hot' but it may not be moving stuff mechanically to the 'hot' position.