Ok so I have now replaced the fan, blower control module and just replaced the blend door actuator with no luck. It blows heat at 90 degrees and no heat at a lower setting’s . Kinda stuck as of now on what next to try? Can someone give a point into the right direction? Thanks

 

Either you replaced the wrong actuator or there’s a problem in the controller or there’s a thermostat that has gone out somewhere would be my guess. What year is your h2?


Edit: this really sounds like a failing temperature sensor. Either the internal cabin sensor or the outdoor sensor. Is your outside temperature sensor reading correctly on the mirror?

The inside one is above the headliner right above where your head would be in the drivers seat. It looks almost like a little speaker grate further back from the o star mic.

I guarantee that’s gonna be your issue otherwise it’s some goofy wiring problem, but your Better off starting with the sensors.

if you scroll down just a little bit on the h2 forum page. There’s a guy with this exact issue.

 

H2 is a 2004 I guess I will replace the cabin air temperature sensor aspiration next.

 

Couple of other considerations. When a blend door or the main air control panel are replaced, they have to recalibrate themselves. A blend door must be connected with the truck off, install the actuator, then connect the plug to it, then turn the key on to accessory (but do not crank) and wait about 60 seconds. The control panel actuates the blend door through its full range to learn the new range. If a blend door actuator is powered in any way before screwing it into place it must first be re-centered to the center mark on the actuator. If it is not centered then it will not correctly calibrate when power is first applied to it. There are also multiple part numbers for the actuators. I think there is a 5 pin one and a 3 pin one. A 5 pin one can be used where a 3 pin was but not the other way around. I've also found on GM trucks (they use the same actuators) that aftermarket actuators are garbage. I've replaced dozens and ever single time (at least about 6) that and aftermarket one was used it had to be replaced again in under a year and at least two did not work right out of the box. You could try disconnecting the battery, let it sit for a half an hour, then reconnecting and turn the key on for about a minute (do not touch any buttons) and hope that it can recalibrate the doors.

Very very uncommon, is the blend door itself inside the air duct housing itself has broken in some way. That is a major project and required removing the entire dash, dash support structure, dash harness, etc all the way to the firewall to replace. Very expensive, invasive, and time consuming project. Technically the heat is "always on" as hot coolant is always circulating through the heater core inside the duct housing and the blend doors just divert none, some, or all of the air through the heater core.

 

There is also a way to calibrate the control panel. You'll have to look it up as I do not remember.

 

Thanks guys I will try to calibrate the actuator first before I move on to the sensor in the headliner which I just picked. I will keep working to and replacing parts until I get it fixed. Thanks again

 

Ok guys so I went to change the Cabin Air Sensor or Aspirator which was my next step in fixing my hvac heating/cooling problem. What I found was great news. When going to change the aspirator through the trim that surrounds the sun roof as the video shows I found the aspirator to be unplugged (I have no idea why it would have be but it was). After plugging the aspirator back up it seemed to fixed the problem. I will keep a constant watch as I hope this was the problem for sure. On to the next problem/fix.

 

Excellent...... the little fan in it is probably failing though which is common. That is the most likely reason someone would have disconnected it. Will probably start randomly making an annoying buzzing sound if that is failing. Pretty easy to replace though and not very expensive.

 

Yes I am thinking the same thing. So I guess I will see if it makes any noises or fails and if it does I will replace it.

 

the fan blades can be popped off a you can try clean the shaft and put a drop of oil. it stops the buzzing. unless its totally shot