What is wrong with the heater?

1996 GMC SAFARI
185,000 MILES
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DAVID88888888
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96 gmc safari - warm air will not blow into passenger compartment - have replaced thermostat and vacuum line - heater core and blower are working properly
Jan 14, 2012 at 5:52 PM
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FIXITMR
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sounds like blend door is not working right.
Jan 14, 2012 at 6:03 PM
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RASMATAZ
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Inspect the air blend/mode/recirc doors/actuators/vacuum hoses-also check the HVAC control module
Jan 14, 2012 at 6:04 PM
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FIXITMR
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read here. http://www.ehow.com/how-does_4779539_troubleshooting-astro-van-heating-problems.html
Jan 14, 2012 at 6:15 PM
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FIXITMR
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are hoses on firewall at core hot?
Jan 14, 2012 at 6:26 PM
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DAVID88888888
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Yes, the hoses are hot.
Jan 14, 2012 at 6:39 PM
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MIKE H R
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heater core could be blocked. disconnect the lines and backflush. If that is the cause do it a few times to get it really cleaned out and the water comes out clear.
Jan 14, 2012 at 10:24 PM
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FIXITMR
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dont sound like core is plugged.
Jan 15, 2012 at 2:59 AM
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FIXITMR
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look for a electric temp control motor undr lower right side of dash on hvac case.
Jan 15, 2012 at 6:15 AM
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MIKE H R
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with heater core eliminated then continue to follow fixitmr on checking the electric control motor.
Jan 15, 2012 at 4:22 PM