Blackened 79

In a previous post, I assumed I was getting hot air coming thru the kick panel vents on my '79, but I was mistaken...the air is actually coming from the HEATER vents !!! When I turn the ignition to 'on', I hear the blower motor
running. Is this normal ? Do I have a faulty heater blower switch ? It seems like it's never totally 'OFF', but always blowing at a low speed. Anyone else have this problem ? Maybe a cable that operates the heater/defroster diverters is broke ???

Help !!!! :mad

mayberg

I think it's normal for that vintage of GM cars to run the blower motor even with the air system off.

rrent

I think Chevy used to call it flow through ventilation -- but I didn't think the fan actually blew air.

As a short term fix you might want to install a valve in or diconnect the heater hoses going to the core -- just in case the heater door is open a bit letting hot air in.

johns73

you could check the vaccume hose that controls the the heater door, mine was disconected and allowed the hot air from the heater core to flow all the time, it should be on the fire wall near the distributor its small about 1/4'' round. Good Luck John :flag

vettfixr

The blower is never completely shut off . Even on the lowest setting it still runs. The heat you are feeling coming out of the heat vent can come from 2 possible sources. The heater core always has hot water flowing through it so installing a manual shutoff valve in the large line will help solve this problem. The second source of significant heat is hot air entering through the intake plenum for the heat/AC system. Here's an older post that I did on the topic. By sealing this area I eliminated 95% of the heat coming into the cockpit. Take a look. http://forums.corvetteforum.com/zerothread?id=362830