No heat

[Navy75]

HELP... it's cold as all get out here in colorado and i can't get the heat to work in my '82 K5.
i put a new thermostat in and finally have hot radiator hoses, then i put a new heater core in 'cause i still wasn't getting any heat in the cab and still no results
any idea's as to what the issue is?
trying to get this fixed so i can go do some winter wheelin but just not into freezing my arse off to do it.

 

[chevyuser74]

make sure the heater core hoses are getting hot, but u probably have a blend door problem

 

[Navy75]

I'm not familiar with the blend door. where is it located and what is the way it should normally operate?

 

[chevyuser74]

this truck have ac or no?

 

[Navy75]

it used to have ac, but the previous owner gutted it. left the stuff one the firewall (can't remember the name of the components at the moment). they just cut the lines and drained the r-12 and removed the part from in front of the radiator (condensor?)

 

[chevyuser74]

the blend door is controlled by a cable u should be able to open ur glove box and see the cable moving when u move the controls, the vent selection is controlled by vacuum on the other hand, does it still switch modes on the vents? and are the heater hoses both of em hot? u should hear the door moving too when u move the selector, move it real quick and see it hits

 

[Navy75]

it does switch between modes. i can't remember if that cable was moving the door or not about to go out and check. i won't be able to check the hoses till tomorrow. if they stay cold am i looking at needing a new water pump?

 

[BlazerBud]

Just to clear the air. You do still have a fan blower correct?

So, there is cold air blowing through the registers, but it don't get hot, correct?

Like previously mentioned, open the hood, feel the heater hoses, if they are supplying hot water to the heater core and returning hot water you have another problem.

Sometimes, the previous owner will disconnect the damper because it is controlled by a vacuum switch. During the summer, even if the AC doesn't work, a faulty vacuum leak can cause the damper to default to the heat-on position when pulling up hill. So, you may be dealing with intentional sabotage.

 

[Navy75]

just checked the temp control and the cable is moving and i could hear the door hit it's stops. i just looked at the routing of the heater hoses and i have one coming off the water pump and one off the radiator. that seems kind of weird to me. i think the older chevy's i had before had one hose off the pump and one off the intake. but it's been a while since i looked at one.

 

[Navy75]

yes i do have a blower (and all speeds do work)
and yes it only blows cold air. i didn't think to check the heater hoses earlier when i was driving around so will have to wait till morning.
where does the blend get it's vacuum from? there are several vacuum lines disconnected under the hood (which is why i think i am running rich as well)

 

[locker1962]

You found the problem....yes one heater hose off the intake (older models near the themostat, TBI models pass side rear of intake) the other to the rad OR the water pump. The hot water comes from the intake then out to the waterpump OR rad.