ihave a 1986 chevette that when i turn defrost on it blows out heat and when i put heater on it blows out only cold air? ihave a 1986 chevette that when i turn defrost on it blows out heat and when i put heater on it blows out only cold air?
You have vacuum line leaks somewhere.
You either have a bad controller or a bad actuator.........
Because your battery terminals are rusty. Have your dad clean them, and then check it again.
blower motor resistor
Most likely a bad or disconnected vacuum hose to the defrost/floor selector in the heater ducting.
Check under the hood for a broken or disconnected vacuum line.
That's because the air pushes against you.
Prob the control switch. I have a similar problem with a 1993 Taurus. U put it on ac it blows out def. Def. blows out vent and none of it really blows out unless it's on high.
Blown Heater Core - The heater fan blows past the heater core and if it has a hole in it your antifreeze ios being blown onto your windshield.
There may be several reasons why the air only blows out the front vents and not on the floor or the defrost on the 2003 Dodge Ram. The fuses may be blown, or the heating coil is not working correctly.
electric defrost, using an electric heater that the air from the evap fans blows over and defrosts the coil, usually time initiated temperature terminated