No heat!

OK.. heres the deal, i have a 1992 S10, and the heat doesn't work. What i mean by that is, it wont blow any heat out. After a while, the truck usually gets warm inside, so i know there must be at least SOME heat coming out, but how do i get it to really BLOW heat out? any please.

OK.. heres the deal, i have a 1992 S10, and the heat doesn't work. What i mean by that is, it wont blow any heat out. After a while, the truck usually gets warm inside, so i know there must be at least SOME heat coming out, but how do i get it to really BLOW heat out? any please.

I assume the fan is working which leaves 2 things. Either a clogged heater core, or the valve that controls the water leading to the heater core.

1st confirm the valve. Have someone slide the temp control up and down and make sure the valve in the engine compartment connected to the inlet line is moving back and fourth. If it is, then you more than likely have a clogged heater core. Simply remove both lines and back flush it with a decent flush mix.

Note: Is your engine temp normal? I.E @ 195f? If not it could be your thermostat being wide open and not allowing the coolant to heat up enough to produce heat in ther core.

Confirm fan blower speeds are working. Truck movement will force some air flow thru core into cab without fan working. check blower motor ground wire connections are clean and tight. That 4 wire plug to resistors (3 speeds) (on air box) connections is not rusty. temp control in mine is cab side of firewall door that controls how much outside air is blown thru heater core. possible air lock in heater core. disconnect upper heater hose engine side, hold high, slowly pour premix coolant in to get most air out. be sure there is some water in coolant as just coolant concentrate may not transfer much heat. maybe need to backflush heater core with water hose.