Cab Heat / Air Conditioning Issue

[KiotiTom1231]

2018 RX6620PC. In addition to the very painful learning curve in plowing snow up/down a gravel hill this past winter, I had to deal with the new machine not allowing the heater and air conditioning to run at the same time. With the heat on full, the interior windows would completely fog up. Hit the AC button on and the air would immediately blow cold. The cold dry air conditioned air would then clear the condensation on the windows, but I would then be freezing my butt off. Hit the AC button off and I would warm up but the moisture on the windows would return.

Dealer said "crack the windows open to let some air in". NOT something you tell someone that just spent the extra $$$ on a heated cab! Just the same, tried it and it did not work.

Air in the HVAC system: Blows from the fan, through the AC evaporator core, either through or around the heater core, then into the cabin. There are two doors tied together in the HVAC system between the AC evaporator core and the heater core that do only one of two things at a time: Either divert ALL air through the heater core or divert ALL air around (bypassing) the heater core, there is no in between or mixture - either fully closed or fully open. When the AC button is turned on, in addition to enabling the AC compressor, those doors divert ALL air around (bypassing) the heater core, when the AC button is turned off, in addition to disabling the AC compressor, those doors divert ALL air through the heater core. Temperature adjustment is achieved by a stepper motor solenoid regulating the amount of coolant flowing through the heater core.

Anyone having this issue? I find it difficult to believe I am the only one with this issue.

 

[Kioti Paul]

It sounds like it is operating as designed. In my opinion-- a very bad design! There have been a couple of threads where people install aftermarket heaters / window defrosters.

Seems to me that it should be pretty easy to modify the wiring - which if Kioti discovers it, will almost certainly void any warranty (whether or not the modification had anything to do with the warranty claim).

The simplest modification would be to unplug the compressor, then run a different wire from the alternator battery lead to the compressor, then to ground. Preferably find an identical plug (many automobiles use the same compressors). otherwise .250 female spade connectors should work. OF COURSE, do NOT cut, mutilate, or modify the original plug or wiring!!! just fold back out of the way (That goes without saying,,,right??)

If you do that, be sure to have a fuse in the positive lead. Plus be sure to remember that the compressor will ALWAYS be engaged, even when the tractor is off (and when cranking)...you will have to unplug the compressor anytime you don't want it running.

Obviously, this is not an ideal fix; but it is quick, easy, and can be (quickly and easily) removed anytime you need warranty work. In addition, I would bet that the conditions where you need the compressor to run with the heater on are few and far apart (if the outside temp is below 35 it won't do any good to run the comp), so for the most part you would just keep the original wiring plugged into the comp.

When the tractor is out of warranty, with a little snooping, it should be quite easy to add an additional switch in parallel with the AC button to either keep the comp on even with the AC button off, or to keep the diverter doors in the heat position with the AC button on.

 

[KiotiTom1231]

That is the same conclusion I came to - operating as designed, just that the logic of the design is badly flawed. The official fix for this would be a change in the code of the controller. The major problem is how in the world do you get Kioti to make a code change like that? The dealer does not appear to be interested in helping. Anyone have contacts direct into Kioti that I could consider pursuing?

Thanks for the workaround suggestion, but the workaround I have implemented is even simpler. Turn the AC off thereby causing the doors to divert the air through the heater core, then unplug the stepper motor that moves those two doors. Now when you turn the AC on those doors do not move to divert the air around the heater core. Problem is I will have to do the unplug every fall, then plug it back in every spring. When out of warranty I could probably install a switch to control that circuit. But really, it would be nice to have it work the way it should.

Still interested in knowing if anyone else is experiencing this issue? Hard for me to believe I am the only one plowing snow in the winter with an RX6620. The orange beast is parked in a 47 degree shop with doors and windows open to let the shop heat dry it out. But once I track in a little snow from my boots, that snow melts and the moisture fogs up ALL the windows. The heater by itself does not cut it, has to have that dry conditioned air to get the moisture off the glass.

 

[KiotiTom1231]

According to my email, someone replied to this thread with "Got it fixed under warranty on my 17 NX". Cannot tell who it is, and I do not know why I am not seeing it here, but can you tell me what specifically they did to fix it?

 

[grsthegreat]

thats weird, my 2010 DK45 can run the heater and when i click on the ac button, i can get rid of the condensation while still getting hot air. i can adjust the temp with the temp dial. Bu running the ac mode, im simply bringing the condenser into play to remove the condensation. i dont know why yours doesnt do this.

 

[NetbyTractor]

That was me. They installed some kit of parts..not sure of the complete content.

 

[kmwahoo]

Mine is doing the same wtf do I do? Please help asap

 

[kmwahoo]

Help me mine is doing the same thing. Fogging up.

 

[kmwahoo]

First time running mine in the snow and it's doing to me. Help

 

[Kioti Dave]

Mine is doing the same wtf do I do? Please help asap

https://www.tractorbynet.com/forums/kioti-owning-operating/415478-nx4510-hst-cab-c-issue.html

Here is a discussion on that issue. It is on page 2. On my NX4510, I had a kit installed on warranty that will allow you to run A/C and get heat at the same time. Has made a huge difference. My windows will be fogged up, and all I need to do is turn on A/C and the windows clear in less than a minute. I also use a 12 volt fan that I plug into the 12 volt outlet. The kit number is in the other discussion. Kioti installed on warranty a month ago.

 

[Kioti Dave]

According to my email, someone replied to this thread with "Got it fixed under warranty on my 17 NX". Cannot tell who it is, and I do not know why I am not seeing it here, but can you tell me what specifically they did to fix it?

https://www.tractorbynet.com/forums/kioti-owning-operating/415478-nx4510-hst-cab-c-issue.html

Here is one of the threads.

 

[KiotiTom1231]

Ok, I just deployed my "workaround" for this winter and thought I would revisit this thread. I am glad to see, in a good way of course, that others are experiencing this issue. Unfortunately the above solution link appears to apply to the NX model, I will be calling the dealer this week to see if an RX model fix is available.

Thanks for the info!

 

[MinnesotaEric]

2018 RX6620PC. In addition to the very painful learning curve in plowing snow up/down a gravel hill this past winter, I had to deal with the new machine not allowing the heater and air conditioning to run at the same time. With the heat on full, the interior windows would completely fog up. Hit the AC button on and the air would immediately blow cold. The cold dry air conditioned air would then clear the condensation on the windows, but I would then be freezing my butt off. Hit the AC button off and I would warm up but the moisture on the windows would return.

Dealer said "crack the windows open to let some air in". NOT something you tell someone that just spent the extra $$$ on a heated cab! Just the same, tried it and it did not work.

Air in the HVAC system: Blows from the fan, through the AC evaporator core, either through or around the heater core, then into the cabin. There are two doors tied together in the HVAC system between the AC evaporator core and the heater core that do only one of two things at a time: Either divert ALL air through the heater core or divert ALL air around (bypassing) the heater core, there is no in between or mixture - either fully closed or fully open. When the AC button is turned on, in addition to enabling the AC compressor, those doors divert ALL air around (bypassing) the heater core, when the AC button is turned off, in addition to disabling the AC compressor, those doors divert ALL air through the heater core. Temperature adjustment is achieved by a stepper motor solenoid regulating the amount of coolant flowing through the heater core.

Anyone having this issue? I find it difficult to believe I am the only one with this issue.

Your description makes it sound as though when the AC button is activated, the blend air door bangs full cold over-coming the user demand position (wherever the driver wants the blend air door set). If this is the case, then I think the cable controlling the bend air door has popped off of where it is supposed to be routed.

Even so, I'm a little baffled by your description and will offer some alternative things to check: If your system is like or even exactly as the HVAC system on the NX series, then I suspect that the cable that controls the blend air door has slipped on the cable biasing the blend door toward the cool side. In other words, when on full warm, the blend air door is really mixing cool air with warm air making sorta-warm air. Then when you hit the AC, and the system is warm enough to allow the thermistor to turn on the AC clutch, the cool air becomes cold, dry air and overwhelms the heated air because again, the blend air flapper is not actually where the knob claims it is.

Question: can you "bottom" or what feels like hitting a stop when the blend air knob is turned toward full cold before the knob itself gets to the coldest setting? If so, then the cable has slipped on the blend air door.

Alternatively, pop the top off the cab (six nuts on an NX series) with the friend to help lift the top off and manually work the HVAC controls to see if something is obstructing closing the blend air door when fully on heat.

 

[KiotiTom1231]

Hello, MinnesotaEric! Small world, you are one of my regular YouTube stops! Thanks for the reply.

There is nothing malfunctioning with this HVAC system, it is functioning as designed. There are no cables to be had in this system, it is all electronics and stepper motors, making the system functionality completely based on software/firmware. So when I say it is functioning as designed, I mean it is functioning in the way that someone coded the logic in the software/firmware. The code that was developed is flawed and needs an update or revision to resolve this.

I purchased the Kioti service manual for this tractor and even that is not up to date on how this system works, the manual is still showing a cabled system. So I had to pop the top off the cab (four nuts on the RX) and determine how the system works. There simply is nothing wrong with how it is functioning except for the fact that a software developer (most likely living in a year-round warm climate) decided that when the AC button is turned on there is no need for ANY air to be pushed through the heater core. Based on Montana winter weather here, I do not agree with the resulting logic that came out of that development decision.

I keep putting off the call to the dealer because I was not at all impressed with them, and they recently got bought out by another dealer, so I am not sure what a phone call will get me. Still going to call, but if for some reason you happen to have a Kioti contact that you may have engaged in the past, I would be grateful if you could share that information with me.

Thanks!!

 

[MinnesotaEric]

Hello, MinnesotaEric! Small world, you are one of my regular YouTube stops! Thanks for the reply.

There is nothing malfunctioning with this HVAC system, it is functioning as designed. There are no cables to be had in this system, it is all electronics and stepper motors, making the system functionality completely based on software/firmware. So when I say it is functioning as designed, I mean it is functioning in the way that someone coded the logic in the software/firmware. The code that was developed is flawed and needs an update or revision to resolve this.

I purchased the Kioti service manual for this tractor and even that is not up to date on how this system works, the manual is still showing a cabled system. So I had to pop the top off the cab (four nuts on the RX) and determine how the system works. There simply is nothing wrong with how it is functioning except for the fact that a software developer (most likely living in a year-round warm climate) decided that when the AC button is turned on there is no need for ANY air to be pushed through the heater core. Based on Montana winter weather here, I do not agree with the resulting logic that came out of that development decision.

I keep putting off the call to the dealer because I was not at all impressed with them, and they recently got bought out by another dealer, so I am not sure what a phone call will get me. Still going to call, but if for some reason you happen to have a Kioti contact that you may have engaged in the past, I would be grateful if you could share that information with me.

Thanks!!

Stepper motor controlled. I would not have guessed that unless I was looking at it. I think you need to make a call to the dealer and ask if they have any HVAC software updates. The whole ECU is behind a firewall and only dealers can update the software (which is a total bummer). Up in north-central Minnesota, I've been using the Kioti dealer in Glyndon MN, but now that Bobcat is selling rebranded Kioti tractors I plan to ask if they can get into the ECU as Bemidji Bobcat is just a hop, skip and a jump away.

If you don't get satisfaction from a local dealer, Kioti has their "five paw" rated dealers who should be able to give you some direction. If that fails, then try calling Kioti directly. I believe Melissa is still doing the customer service work (and if I'm wrong, let me know LOL ).

Anyway, thanks for watching!

 

[kioti617]

That was me. They installed some kit of parts..not sure of the complete content.

I just had mine repaired under warranty. I believe it had something to do with rewiring and the dealer ordered a kit from Kioti. I am curious after your repair does the indicator light on your air conditioner come on when running the heat on hot and engaging the A/C button? Mine ran at idle for 45 minutes and the indicator light didn't come on. It was below zero last night and zero when I started the tractor.

I truly love my NX6010

 

[NetbyTractor]

The light comes on if you turn it on (push the button), but doesn't come on if you don't turn it on.

 

[kioti617]

The light comes on if you turn it on (push the button), but doesn't come on if you don't turn it on.

Hmmm.....the light doesn't come on even though I had the warranty repair. I called the dealership and inquired today and was told that the light didn't need to come on with the repair they did. Seems to me if you press the button for power it should the green indicator should lite up.

Thanks for your reply.

 

[Threepoint]

Hmmm.....the light doesn't come on even though I had the warranty repair. I called the dealership and inquired today and was told that the light didn't need to come on with the repair they did. Seems to me if you press the button for power it should the green indicator should lite up.

Thanks for your reply.

Kioti617, sounds odd to me, too. On my 2014 NX, the AC light toggles on and off along with the AC, regardless of where the temperature dial is set. But I've never had a problem running both heat and AC at the same time.

 

[justman777]

Hmmm.....the light doesn't come on even though I had the warranty repair. I called the dealership and inquired today and was told that the light didn't need to come on with the repair they did. Seems to me if you press the button for power it should the green indicator should lite up.

Thanks for your reply.

Umm...the light on the AC button should come on if you press the button. The dealer doesn't know what he's talking about, or is confused as to what you are asking. I think you have a warranty issue to contend with one way or the other---your AC light is broken, or whatever they installed was installed incorrectly.

The kit that I had installed was TE16-A0083A, and I'm reasonably sure they have something similar for the RX series or any other cab unit. I wouldn't be surprised if it was the same unit. It comes with a whole other control assembly (knobs and such) as well as a new blend door/gate for the AC. The control assembly allows the AC compressor to be activated at the same time as the heater. The old control assembly didn't do that. You either got hot air or you got super cold air.

I reviewed the install instructions for the kit with the technician, and came to the conclusion I could do the install myself if I needed to. If you're reasonably handy, you should be able to do the same.