Honda HVAC Blend Door Actuators

I had no heat in my 2008 Honda CR-v, and the driver's side of my 2010 Honda Odyssey was moving between hot and cool constantly.

There are little actuators that move the blend door(s) for heat and cool in Hondas. Back when I was a mechanic I would always try to repair them, because most of the time the grease that they use at the factory just dries out in them. They don't really wear out as you are lead to believe. They have tiny little brushed DC motors in them. The same kind of motor that makes your power mirrors work. And power mirror actuators almost never go bad.

There are only (3) gears in the actuator, and the little motor has a worm gear on it (NOTE: THE MOTOR IS DC, MARK THE MOTOR SO YOU KNOW EXACTLY WHICH WAY TO REINSTALL IT. IF YOU ROTATE THE MOTOR, IT WILL RUN IN BACKWARDS. IF THIS HAPPENS THE ACTUATOR WILL MOVE ONE WAY, WHEN INSTALLED, AND STOP). The way the system works is signal and feedback. When you move the dial to heat, cool, or somewhere in-between, it causes the actuator to move. There is feedback to the A/C control head that controls the actuator. If you put it in the middle, it's looking for a (5) volt feedback signal. So it will drive the motor in the direction it needs to until it gets the feedback voltage it's looking for.

If there is no feedback, it won't move at all. In my 2008, it wouldn't move at all. So, I removed the actuator. This is a picture of the actuator out of the 2010 Odyssey, but it's OK, because they are the same inside.

To open the actuator there are little plastic clips all the way around on the outside, and there are two on either side of the connector. These usually break when you try to open the actuator. Don't worry though, the screws that hold the actuator to the bracket also work to hold the actuator together. As long as you don't break all of them, you should be OK. Otherwise you'll have to rig it with Zip-Ties or something like that.

There is an output gear that connects to the linkage. On that gear is a slip ring made of a resistive material. These pictures I grabbed off the internet, because I didn't take pictures of mine. It's way too windy outside and the temperature is dropping, so I wanted to get both cars fixed quickly! Whoever was working on these actuators went CRAZY with the grease. I never add grease to the gears because they are plastic, and slow moving, and grease is what causes the problems in the first place.

After around 10 years the grease on the slip ring starts to get dry and hard. And it keeps the little contacts from contacting the ring.

The fix is really simple. Clean all the grease off of the slip ring with a paper towel. Clean the contacts for the slip ring as well. Then bend the little contacts up a little bit more than they were to begin with, but not too far.

Then to grease the slip ring, I just use a little petroleum jelly. Some people like to use dielectric grease, but that's expensive, and not really needed because the slip ring only has around 10 volts on it anyway.

Snap it back together, and plug it in under the dash, but don't mount it! Check and make sure that it can be moved to all positions with your hot/cool dial, or by running the setpoint up and down if you have automatic A/C. Just make sure that it can move correctly.

If it works, reinstall it and test to make sure that the blend door isn't binding, and you have it installed correctly.

That's it, you just saved yourself a ton of money! These actuators cost around $150 after market, and the one for the Odyssey was listed at $190.

Also, because of the government created supply chain crisis, you could wait quite a while to get one of these parts.

I'm not sure what the labor to replace would be now, but if you went to a shop, you would probably be looking at $300 to get one replaced. Or, you can take a little time and fix it yourself.

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