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2013 JKU Heater Fan Always On Full Blast

2K views 4 replies 3 participants last post by  zayres 
#1 ·
Hi there!

I got my 2013 JKU a few months back and have really been enjoying it. This forum has been a tremendous source of information so far, but I've encountered a problem for which my searching has turned up nothing. I hope you can offer suggestions!

First off, it has been raining here for DAYS. Hard rain. My JKU is parked outside. Perhaps its related? This issue reared its head this morning, as it wasn't doing this last night when I came home.

Currently, any time the key is in the ignition and the power is turned on, the cabin AC/Heat fan is running full blast. The position of the fan speed dial doesn't change a thing, it's blasting no matter the position of that or any other dial. All other aspects of the system still seem to work as expected.

Any thoughts?

As a side note, this morning when I discovered this problem, I also noticed that my freedom top front panels had been letting some water in at the middle seam between the two front panels, as there were drips and a bit of pooling in the low areas of the console around the gear shift lever and the 4WD lever. There was also some water in the cubby hole in the center stack where the power window switches would be if I had them. I didn't find water anywhere else like on or around the cabin control dials. I haven't had those panels off since last fall, and it's seen some rain since then, but perhaps not like this.

Do you think there's a relationship between the water intrusion and the fan issue, or are they both just cropping up now as a result of the biblical rain we're having? Or is the fan issue not related to the rain at all?

Any advice or direction to start looking would be greatly appreciated. I'd love to tackle this problem myself rather than admit defeat and take it to someone.

Thanks!
 
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#2 ·
hmm you got water behind the dash. I would try and reset the computer control systems on your jeep first. to do this disconnect the positive and negative with a 10mm socket, then put the key in acc and press the brake for 30 seconds. Now wait 30min then reconnect the battery.

If it still runs the jeep hvac fan full blast, keep the heat on high for a couple of days and let everything dry out.

If that still does not do it, you might have to replace the blower motor resistor or HVAC control unit which involves taking your dash apart. JKU hvac control unit is all digital now so its easy to replace ( 2 electrical cable harnesses I believe.)

start with the resistor:
https://www.amazon.com/2013-Jeep-Wr...ncoding=UTF8&ie=UTF8&newVehicle=1&vehicleId=1

If that does not work might have to replace the HVAC control unit (does it give a blink code on the a/c yellow LED when you first start up?)

I would also take off your freedom panels and clean the gaskets with soap and water the apply some of this stuff: https://www.amazon.com/303-Rubber-Protectant-Conditioner-Weather/dp/B00T44D1R2
Make sure the screws that go through the sound bar that hold on the freedom panels are hand tight!
 
#3 ·
I had this same problem this winter. The fix for me was to replace the HVAC control unit.
Really easy to do.
4 screws to undo the dash and get to the unit.
Grab the part number off the unit you have and order a new one.
Plug it in, wait about a minute for it to cycle and calibrate and then you're good to go.
 
#4 ·
Thanks for the directions to get started on this! The rain has finally cleared out and it looks like it's all clear for the next week, so I have high hopes to resolve it with this info.
@nightowl2000..
hmm you got water behind the dash.
I agree. I thought about it some more and the water in the cubby where the power window switches would be was telling. There are holes in the bottom of that opening that seat the little rubber tray that goes in there, and it is directly above the affected controls, so I'd bet that is where the water got in, as it dripped down from the freedom panel seam.

I would try and reset the computer control systems on your jeep first. to do this disconnect the positive and negative with a 10mm socket, then put the key in acc and press the brake for 30 seconds. Now wait 30min then reconnect the battery.
I'll give this a shot tonight and report back!

If that does not work might have to replace the HVAC control unit (does it give a blink code on the a/c yellow LED when you first start up?)
I'm glad you asked, I have noticed that the yellow light on the blower control dial (far left) does blink when I press it to turn on recirculation, before staying on. I don't recall if it blinks when I first start the Jeep, but I'll find out. I will take a closer look at how the lights on the three dials behave and report back. What does the blinking mean? I don't know why it didn't click that the blinking was an indication of some kind!

I would also take off your freedom panels and clean the gaskets with soap and water the apply some of this stuff
Great suggestion. After I got past the initial frustration and had a chance to think on it some more, directly prior to these days of rain, we had a couple of days of ice/sleet. I'm thinking that the ice conditions must have worked to loosen up the gaskets, allowing the water to get through when we got 5+ inches of rain in the following days. I'll clean the gaskets and treat them with the rubber conditioner!
@GZilla

I had this same problem this winter. The fix for me was to replace the HVAC control unit.
I'm glad to hear you've been here and seen this gremlin before. Definitely something I love about the Wrangler community so far. Never alone. I'll be digging in to this soon and will post back on how it goes!

Thanks again!
 
#5 ·
Just wanted to provide an update, I finally replaced the HVAC control unit and it resolved the problem.

It really is an easy swap, about 15 minutes.

I looked everywhere short of the dealer. At one point I thought I'd found a non-OEM replacement for ~$50, but after ordering it, mymoparparts.com told me the part had been 'superseded', and the available replacement would be $120, plus shipping. That was frustrating, but eventually my desire to fix it won out, so I spent the money, and now it's fixed.

Thanks for the advice to those who posted, and I hope this thread proves useful for anyone reading in the future!
 
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