Heater control/blend door

TomDabb said:

So I’ve done a lot of work and yes replaced many parts to get heat in my ‘13 JKU.
Heater core included - after this replacement I seem to have Only full on heat or cool. In other words I expected the temperature control dial was done. Apparently, it was fine. But that was confirmed only after I replaced the control unit - ie the three knob assemble.
I believe the blend door is functional. But why only full heat or full cool?
Help!



Sent from my iPhone using WAYALIFE mobile app

Click to expand...

sipafz said:

Just to be clear, the blower work at all speeds?

Click to expand...

TomDabb said:

Blower fan motor works very well on all speeds


Sent from my iPhone using WAYALIFE mobile app

Click to expand...

sipafz said:

Is the blend door actuator working? With the key in the run position, engine not running and blower fan off, can you hear the actuator moving on the drivers side when you turn the adjustment knob one detent at a time?

Also, any clicking noises during actuation?

Can you hear the blend door moving?

You should be able to hear both the actuator motor and blend door move as you adjust the hot/cold knob. Unfortunately you have to start taking things apart to see anything.

Click to expand...

TomDabb said:

The blend door only moves at extreme cold and hot. That makes sense based on what I experience.
No clicking noise at all in between

That would seem to me the blend door motor is functioning.....

I noticed you’re in WI, my sons a junior at Marquette.

Sent from my iPhone using WAYALIFE mobile app

Click to expand...

TomDabb said:

I noticed you’re in WI, my sons a junior at Marquette.

Click to expand...

sipafz said:

We are about 30min north of downtown. How does he like it and what’s his major?

Click to expand...

TomDabb said:

He likes it. What also helped the decision honestly was a n academic scholarship.
But he’s made some good life time friends as well. I’m heading out for a visit mid April.
I’m impressed with the school. I’d recommend it to others. He’s in commercial investments business major and a minor in accounting, I believe


Sent from my iPhone using WAYALIFE mobile app

Click to expand...

sipafz said:

So it only moves when you turn the knob to the extremes and nothing in between, meaning if you’re all the way cold and move one click toward hot, nothing happens?

When was the last time you disconnected your battery?

I’m assuming that you didn’t take the blend door actuator off the air distribution housing when you changed out the heater core?

Click to expand...

sipafz said:

Well, that’s good to hear, especially about the academic scholarship! My daughter is a high school freshman so we are starting to discuss colleges and even have a visit setup for this summer at Michigan. She has some big dreams (NASA Engineer) so we are trying to be proactive. My wife works downtown just east of the campus, right on the lake front. Milwaukee is a great place to be in the summer with all the festivals, but April... not much going on. I’d say look me up for some wheeling, but this area is a dead zone. Three hours to the north is the closest place to find some mild opportunities.

Click to expand...

TomDabb said:

Didn’t see the later part of your comment / I haven’t disconnected it since the heater core replacement - it seems the heat/cool temp control stopped fully functioning right after. But why doesn’t that make any sense? Or does it?
On the passenger side, to get to the core I needed to spilt open the plastic duct that carry’s the air from the heater core towards your feet. Carefully I removed it and placing it back in place. The clips let’s you split it apart to access the clips on the heater box itself.

I guess unless you’ve done that last part, it would make sense to you ...


Sent from my iPhone using WAYALIFE mobile app

Click to expand...

sipafz said:

I would disconnect the battery, negative first and then positive. Wait a minute or two and reconnect. That should reset the ECU:

https://www.quadratec.com/c/reference/jeep-ecu-electronic-control-unit-reset

Then test. It might be as simple as resetting the system.

Click to expand...

TomDabb said:

NASA Engineer - I’m Civil, but Structural by profession but 17 years ago switched careers.
Does she joke around saying she wants to be a rocket scientist, lol. I’d take that quite seriously.

I’ll likely stay at The Knickerbocker on the Lake - unless you say , absolutely not. Thanks for your help w my heater.

Click to expand...

TomDabb said:

That’s great and simple. Check it out before leaving for work / and be back here to update.
Cheers!

Click to expand...

sipafz said:

It’s no joke to her although she hasn’t decided whether to focus on aerospace engineering or computer programming. Either way I think she will need both.

I’ve never been to the Knick, but my wife said she had a good business lunch there last year.

No problem, happy to help if I can. I had to replace the air distribution housing in my wife’s KK a few years ago:

View attachment 292296

The teeth sheared off the air handler door:

View attachment 292297




I hope it’s that simple!

Click to expand...

rmilobrown said:

I have a similar problem with my 2015 JKUR. First I lost all control of heat and cold, drivers side blend door actuator not moving. I replaced the bda with a Doorman unit from Amazon. After installation, the rear defrost light would blink every time I started the Jeep for about 30 seconds then function normally. Maybe a day or two later the blinking light stopped and I only had full hot or full cold just like the OP. I momentarily disconnected the negative lead to the battery which got me back to blinking light followed by operational temp control for a day or two. I am back to full hot or cold! Hope we can learn something from all of our experience.

HAPPYTRAILS

Click to expand...

TomDabb said:

Ditto that!
Battery now disconnected....results v soon
WAVE from NJ

Update.....no change after disconnecting the battery - let’s see if time on the road will make any difference.

Sent from my iPhone using WAYALIFE mobile app

Click to expand...

sipafz said:

At this point I pick up a new actuator and keep the receipt. Pull the drivers side kick panel and metal plate behind the panel. Unscrew the actuator,disconnect from the linkage and test operation. If it doesn't move with each click of the adjustment knob, then plug in the new unit and test. If the actuator is not the problem then visually check the linkage and and blend door spur for damage and make sure the blend door moves freely by hand.

Click to expand...