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Discussion Starter · #1 · (Edited)
I bought a 2009 coupe G5 a couple years back. It was the summertime, so I checked to make sure the A/C worked. The air was beautifully cold. I didn't think to check the heat.

As it turns out, the heat doesn't work. When I turn the temperature knob to the right, there's no change in temperature. I don't hear any knocking and the temperature is consistent across all the vents. After some research, it seems that my problem may be the blend door actuator. So far, I've had a hard time figuring out exactly where it is, and a lot of people say you need to dismantle the entire dashboard to get to it.

Before doing something stupid like that, I wanted to see if anyone else had any ideas on this.

I don't even necessarily care about repairing this. I'd be fine with reaching into the machinery and manually moving the door if that's possible. I just need some way to get heat so my windows don't fog.

Thanks.

EDIT: It's probably relevant to mention that both heater hoses are hot.
 

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2007 G5 GT in Fusion Orange. Lightly modded
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I would check 2 things.

#1 Look at the COOLANT LEVEL - If this is low, there may not be enough coolant to circulate through the heater core. The result is warm air in the heater core. Unfortunately, this doesn't do much to warm the freezing cold air in the northern climates.

#2 Check to see if the Coolant is ORANGE. If it is, you MAY have an issue with old coolant that uses O.A.T. type of coolant (also known as "Organic Acid Technology"). If it is this stuff, try to get it all out and replace it with a universal type of coolant. The coolants which use O.A.T. break down when there is an air gap in the hot, pressurized system. This results in little floating pieces of 💩 in your coolant. When they settle, they coagulate; resulting in a gel-like mess that will NOT come out of the 1) -> radiator or the 2) -> heater core. If there is SOME flow through either of these, then running your coolant with a very light acid (Vinegar or Wood Bleach) will help break this garbage up. Chances are, if this is the case AND you aren't feeling any heat, the radiator and/or heater core will need to be replaced.

This is my thread from TCG, back in 2013 dealing with an Orange Coolant (DEXCool) problem. Please note post #7.

My DEX-Cool Thread on TheChicagoGarage.com
 

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I had the blend door break on my car. Not the hot/cold one, but the one that redirects the air flow from the floor/vents/windshield.

However, your problem is most likely the blend door actuator. You'll find it if you go under the dash on the drivers side. It is on the hvac unit, which is right behind the radio. There are two actuators; one for the temp and one for the vents. The temp one is the lower one. It is held on by a few screws. If you remove the actuator, you will be able to rotate the blend door shaft by hand. Go ahead and warm the engine up and give it a try. The actuators aren't very expensive, and relatively easy to replace. The hardest part is lying on your back in the footwell with your hands up in the dash.

On your G5, the engine coolant is always circulating through the heater core in the dash. Changing the knob from cool to hot doesn't change the flow of coolant; it only moves a blend door that controls how much of your cabin air moves through the heater core. Since both of your heater hoses are hot, there is probably nothing wrong with your coolant.
 
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