Hvac Problem

[MOSSYOAK]

Hello all,

 

 

here's what I have so far. I just purchased a 2000 GMC Sierra 4x4 with 188,000 miles. The truck stopped blowing heat. Fan speed controls work as do a/c. Both heater core lines inside engine bay are hot, I flushed the coolant today and flushed heater core with a garden hose and water passed through. I also replaced the thermostat today. The heat quit working BEFORE I did these things.

 

One other thing, It seems to blow warmer air out of the floor vents and fairly cold air out of the front dash vents and ice cold air out of the defrost vents all on the same heat setting???

 

What could it be and where do I go next?

 

Any and all help very much appreciated!!!!!!!

[frupp]

Does the heater core get hot? If yes, it sounds like there isn't any air flow through the heater core. If it doesn't get hot then there isn't any coolant flowing through it. Maybe an air block?

[MOSSYOAK]

Does the heater core get hot? If yes, it sounds like there isn't any air flow through the heater core. If it doesn't get hot then there isn't any coolant flowing through it. Maybe an air block?

 

 

The heater core gets warm but not "hot" I just found the problem but now I gotta ask why? lol

 

The plug for the A/C Heater blend door actuator was unplugged, coiled up and shoved up inside the dash, so I plugged it in and now I have heat.........

[frupp]

Good. But, does the AC now work? I don't know why the wire for the blend door would be unplugged unless this was the way to get the AC to work.

[MOSSYOAK]

Good. But, does the AC now work? I don't know why the wire for the blend door would be unplugged unless this was the way to get the AC to work.

 

Hmmmmm...... Good question, I didn't check that. I'll keep you updated shortly

[MOSSYOAK]

hmmm, A/C works too, wierd.

[Slabi]

Maybe someone had the dash out for some type of repair (heater core etc...) and it was just overlooked.

Cross your fingers it's working up to par...Common issues on these trucks.