No heat!
 

Needing some advice, direction, please help. Good day everyone, I recently joined this forum because I have turned into a s10 blazer freak, used to hate the damn thing, now I cant stop wrenching on it! I am having issues with my hvac regarding my heater. Blower works great, a/c is charged and works amazing, I just cant seem to get my heater to blow any kind of hot, even warm air. I have changed out actuators, vacuum lines, flushed heater core and cooling system, new thermostat and water pump, you name it, still nothing. Very frustrating! I have read thru the forum, google, cant seem to figure it out. Thanks for your time
https://cimg1.ibsrv.net/gimg/blazerf...3678688195.jpg

Have you checked the blend door actuator? Either it has failed or perhaps the controls for it failed?

Welcome to the Blazerforum.

Moved as per rules in the New Member section.

Changing through all the HVAC settings does yield the correct results?

Defrost does defrost, while the other settings blow air where it should be?
Then the fan does work on all these settings?
Does the heater core get hot? or are both lines to and from the heater core on the engine side hot?

If yes, Christine has probably pointed to the problem.

+1 on feel the heater hoses at the firewall in the engine compartment and see if they are hot after the engine gets up to temp.

George

+2 on the heater hoses. After driving for a while, one heater hose/supply/ should be hot and the other one /return/ should be hot but not as hot as the supply. This would indicate that the water from the water pump is flowing as it should through the heater core. If the supply is HOT and the return is cool or slightly warm indicates the heater core is clogged and not allowing the water to pass through it. That would explain why you are not getting any heat. So if both hoses are hot, that would indicate the heater core is good and the problem is elsewhere. See above.

+3 on checking the heater hoses. It is definitive on whether there is heat to be transferred to the cabin and it is easy to do! :)

My apologies for not responding back to you and everyone else that was trying to assist, Working 7 days a week..... i Am going to pull the actuator again, I have exhausted all other possibilities multiple times. Really frustrating to say the least...

If the enclosure for the HVAC system in the engine compartment has either the resistor block or just an access panel on the top on the passenger compartment side of the evaporator, you can remove it and look down on top of the blend door. You can then turn on the HVAC system and then change the temperature settings and see if the door changes position. If nothing else you can with a long screw driver reach in and manually move the door to full heat so you will be warm until you can replace the blend door actuator.

This assumes the control electronics are otherwise working fine.

I did also try replacing the servo/dial that controls hot and cold from the dash. I will attempt what you just described, I appreciate and thank you.
https://cimg2.ibsrv.net/gimg/blazerf...f6889a32de.jpg
Why i didnt resolve heat issue this last weekend, front end rebuildhttps://cimg7.ibsrv.net/gimg/blazerf...9ffa58083b.jpg