Heater not working on driver's side only

Hello Joe, I changed the actuator on the blend door thinking it might be the problem it was not, I pulled the heater core out, cleaned it out added cleaner and flushed it out before reinstalling it in the car. Still only heat on the passenger side of the car the heat on passenger side will work on defrost, front facing, and floor it will also change from cold to hot. The driver's side will switch all three positions also but only blow cold air. I pulled the actuator motor off and worked the blend door back and forth and it works fine.

Joe,

I have moved the actuator door back and forth, it moves freely, and it functions normal on the passenger's side, one way the air is hot and the other way the air is cold. On the driver's side when I move the actuator door the air stays cold either way, it just does not make sense. I know the serpentine belt is turning okay. Thermostat is okay, the heat gauge is always normal. The air flow from the vents is strong on all three ports. When I had the heater core out, I could look inside a little. It was kind of hard to see but I could not see any blockage and it does seem to blow air great. I was reading some info that said the heater core could have been plugged on one side that is why I removed it from the car and took it into my house and cleaned it, but it was not really dirty and when I flushed it out after cleaning I ran hot water through the core and it was hot completely through so I knew it was not plugged. Jim

Joe, like I said, it does not sound right but I took the heater core out of the car cleaned with Prestone cleaner. I flushed it with hot water from a hose, it flushed out both ways freely and the heater core got hot completely throughout as I made sure to feel the core as I was flushing it out. I am going to change the thermostat and the water pump just because they have never been changed, I don't know if it will make any difference.

Thanks, I will be looking for the problem.

Joe, yes, I do have a scope. I used it to look in the heater core compartment I couldn't see anything damaged. All I could see was the A/C condenser. Nothing seems to look off. The blend door like you said is a single door hinged on one side and the actuator is on the other. I took the actuator off and moved the door by hand, and it seemed to move fine. Should I be able to see the A/C condenser from the heater core compartment with the heat set on hot or should it be covered by another door inside. Thanks, Jim

I had the heater core out of the car when I looked into the core cavity. The door for hot and cold opens and closes. What I was wondering is there another door toward the front of the heater box where the a/c core is located, as I can see the A/C core when looking in heater core cavity. I wondered if another door closed the A/C core off when the heat was turned on. I hope I am explaining this good enough so you can get the idea.

I will check the air inlet door actuator because the other doors seem to be working. Thanks, I will let you know.