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-   -   Heater Not Blowing Hot Air (https://67-72chevytrucks.com/vboard/showthread.php?t=606074)

MashTheGas 72 11-28-2013 03:56 PM
Heater Not Blowing Hot Air
 
I have a 72 GMC pickup that I just changed out my heater core with a new one since the old one was leaking. I installed the new one and now my heater want blow anything but cold air. I noticed there are a couple of electrical connections and something that looks like a relay on the right side of the heater core box. Just wondering if that can go bad. If you shake it sounds like something is loose inside. The truck did come with air just not hooked up right now. I would really appreciate any advice. Thanks in advance.

zeldman 11-28-2013 04:24 PM
Re: Heater Not Blowing Hot Air
 
Ok, so the blower is working, just not getting heat. Start with the simple things like coolant level. After that make sure the valve on the heater hose is moving. Since it has A/C, there should be a valve on the heater hose that shuts off the water when the A/C is on. Those has been known to stick before especially when you really need heat.

MashTheGas 72 11-28-2013 04:28 PM
Re: Heater Not Blowing Hot Air
 
Water level is good and I took the valve out for now. The blower works great.

Mister-B 11-28-2013 04:29 PM
Re: Heater Not Blowing Hot Air
 
Check your control and all the cables. Something may have broken or wiggled free, and it isn't moving the door that allows heat to come out, and is instead blowing the cold air

MashTheGas 72 11-28-2013 04:32 PM
Re: Heater Not Blowing Hot Air
 
I will check that right now and let you know. Thanks alot for your time.

zeldman 11-28-2013 04:47 PM
Re: Heater Not Blowing Hot Air
 
After the controls and cables, the next thing will be the door that allows heat to come out. These are plastic and are known to break. That is inside, under the dash. Check the lever on top of the box and see if it moves. If it does, then it might be a broken door.

MashTheGas 72 11-28-2013 05:05 PM
Re: Heater Not Blowing Hot Air
 
"Mister" You nailed it bud. The door wasn't moving like it should have been. Blows much needed hot air now. Thanks alot.

MashTheGas 72 11-28-2013 05:06 PM
Re: Heater Not Blowing Hot Air
 
Quote:
Originally Posted by zeldman (Post 6392958)
After the controls and cables, the next thing will be the door that allows heat to come out. These are plastic and are known to break. That is inside, under the dash. Check the lever on top of the box and see if it moves. If it does, then it might be a broken door.
Thanks alot it was the door. Wasn't closing like it should.

zeldman 11-28-2013 05:40 PM
Re: Heater Not Blowing Hot Air
 
Happy to have been a little help. Enjoy the heat..!!

Mister-B 11-28-2013 06:18 PM
Re: Heater Not Blowing Hot Air
 
Quote:
Originally Posted by MashTheGas 72 (Post 6392975)
"Mister" You nailed it bud. The door wasn't moving like it should have been. Blows much needed hot air now. Thanks alot.
Glad to hear it


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