Front heater blend door actuator

204explorer · Post by **204explorer** » Sat Sep 30, 2017 7:43 am

As the weather turns colder, I noticed that my front heater is not blowing any warm air. The rear heater is working normal.
My heater core is not plugged, I have good flow trough the heater core.
I noticed that my blend door actuator on the bottom of the HVAC box is not moving. My van is a 95 L400 Royal exceed with the auto temperature control system. I removed the actuator from the van. I checked the six wires from the controller to the actuator and they check out ok. I also have a voltage output from the controller. So I pretty much narrowed it down to the actuator.
I opened up the actuator and inspected it. I powered the little electric motor with a 12 volt supply and it turns without any problems both ways when the polarity is reversed. After assembling the actuator I plugged it back in and tested it. The system is working 100%.
I have not really done anything to the actuator other than taking it apart.
The Denso part number on the actuator is 063700-5391. I found a Mitsubishi part number on a website, MB657424, I am not 100% sure this is the correct number. I would like to install a new actuator if possible because I dont think this one is going to last a lot longer and it is not a lot of fun to remove it.
Have any of you replaced this actuator before or know where I can get one?
Thanks for your help.

poochike · Post by **poochike** » Sat Sep 30, 2017 8:45 am

I've never had to change that, but I get most of my parts through Impexjapan or amayama (which is easier to navigate). You can also try Steven @ Rising Sun or Mardy @ amazing auto. It'll cost a bit more from them, but faster.

Good luck

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204explorer · Post by **204explorer** » Sat Sep 30, 2017 9:32 am

Thanks a lot for your help. I was on amayama before but the part was listed a discontinued. This time I searched the Denso part number and it comes up as available. I never ordered anything from that website or form Japan for that matter. I am always worried about getting a huge bill for brokerage. What has your experience been? Its a pretty small part and list price is US$61, so not too expensive. I am probably going to order it.

kaizi1990 · Post by **kaizi1990** » Sat Sep 30, 2017 9:34 am

I'm having the same problem except that the rear is not blowing warm air and the front is minimal heat.
How did you eliminate the heater core not plugged?

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204explorer · Post by **204explorer** » Sat Sep 30, 2017 10:00 am

Kaizi, testing the heater core in my van was very easy. The way I have my espar heater hooked up it requires all the coolant to flow trough the front heater core. So I simply turned my espar heater on made sure it fired up. With a plugged heater core the espar would not fire up. After ten minutes the heater core was nice and warm. I then turned on the fan and operated the linkage by hand. It instantly changes from hot air coming out of the vents to cold air coTming out of the vents. If you look at the very bottom of you HVAC box, there is a bunch of linkages all activated by that actuator. If you change your heat settings all the way from hot to cold and those linkages are not moving at all, you have the same problem.
Otherwise you should make sure that your engine temp is going to the normal range when driving. If not this indicates a thermostat issue. You could also experience an air lock . There is a bleed screw in your engine area beside the top left corner of your cab air intake opening. If you crack that open there should be coolant and no air coming out. (engine might have to run. Cant remember exactly)
You can also check the temperature of your engine and compare it to both hoses going to and coming from the heater core. Should be close to the same temperature.

kaizi1990 · Post by **kaizi1990** » Sat Sep 30, 2017 1:29 pm

I've only gotten as far as taking off the glove box and found the actuator for outside air and recirculating cabin air.
What part of the panel you took off to see all that?

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204explorer · Post by **204explorer** » Sun Oct 01, 2017 8:27 am

The blend door actuator is at the very bottom of the HVAC box at the centre of the console.
My van has a stack of three control modules mounted to the floor, the ABS controller, Airbag controller and transmission controller.
The actuator is exactly above these controllers. I removed them (I did not unplug the airbag controller with the red wires) and also removed the ducting for the floor vents and then you have perfect access to the actuator.

poochike · Post by **poochike** » Sun Oct 01, 2017 11:11 am

204explorer wrote:Thanks a lot for your help. I was on amayama before but the part was listed a discontinued. This time I searched the Denso part number and it comes up as available. I never ordered anything from that website or form Japan for that matter. I am always worried about getting a huge bill for brokerage. What has your experience been? Its a pretty small part and list price is US$61, so not too expensive. I am probably going to order it.

I've never had an issue with duty ordering from Japan and have made some $500+ orders. The only thing with Impexjapan is you need to watch your account as they always add a couple if bucks to the shipping after your initial payment and they won't ship it until that's paid.

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