NX4510 HST Cab A/C issue

[YLee Kioti]

There is a lot of heat within a small confined space.
The rad., condenser, hyd. cooler, oil cooler all looking for air for max heat rejection.
Watched a Yanmar video on how the mini-ex relocated the A/C condenser away so it will reject heat with no other restrictions.
unfortunately our machines have little real estate for placement anywhere else.

Glad you're up and running.....

 

[Kioti Dave]

For anyone searching this issue, just wanted to weigh in, this is almost always the problem. I've had the "hot air" issue in my NX several times, every single time it was too much crud in the fins. Couldn't see it, but when I blew it out.. Well, lots of crud came out and the AC worked fine again. Seems this tractor is relatively sensitive to crud on the AC coil, more so than expected (for me). Just blow it out first, that's likely the problem and it's an easy fix. The compressor will engage and disengage quickly if your fins are plugged, seems to spin up, start to cool, then shut right back down (probably because it's too hot). Anyway, it's an easy fix, so that's good news (except the last time it happened I was 2 miles from the house/air compressor and it was a solid 98 degrees out, nothing like a cab with no AC to give you a nice case of heat stroke).

Overtaxed. I agree with your assessment. It seems the A/C coil is maybe too small and very sensitive to any blockage. An easy fix. Just need to blow out regularly.

 

[justman777]

For anyone searching this issue, just wanted to weigh in, this is almost always the problem. I've had the "hot air" issue in my NX several times, every single time it was too much crud in the fins. Couldn't see it, but when I blew it out.. Well, lots of crud came out and the AC worked fine again. Seems this tractor is relatively sensitive to crud on the AC coil, more so than expected (for me). Just blow it out first, that's likely the problem and it's an easy fix. The compressor will engage and disengage quickly if your fins are plugged, seems to spin up, start to cool, then shut right back down (probably because it's too hot). Anyway, it's an easy fix, so that's good news (except the last time it happened I was 2 miles from the house/air compressor and it was a solid 98 degrees out, nothing like a cab with no AC to give you a nice case of heat stroke).

That's the truth! If I was going to be working away from the house, I'd take my portable air tank and wand with me. Should have enough air to blow it out a few times.

 

[Kioti Dave]

Thanks. I was asking my dealer about that kit. I will have to get one. Thanks for the info. I think the A/C problem might be in the cab. Is like that when the cab starts off really hot. Do you have remotes on your NX. Mine seem to run really hot, near 175 degrees. You have much warmer weather than I do in Canada. So far pretty happy with NX.

Well, got the kit installed today so that I can have heat at the same time as running the A/C. Hopefully this will help with the fogging issue I had last winter. Kit was done on warranty and was very simple to install. Remove roof, controller, one actuator and wiring harness. Total about 1.5 hours and done. Will update on impact to fogging windows. Also bought a cheap 12 volt fan that I will have running in the cab as well.

 

[MinnesotaEric]

The A/C on my 2016 NX will 'flicker' on and off. The problem seems intermittent. Dealer came and looked at it, and it behaved when he was looking at it. Only after he left did it start acting up. High and low side pressure seemed ok. Screens are completely clear of debris. When it works, blows really cold, but sometimes, the compressor turns on and off every few seconds, sometimes it will do this for a full hour, and cab will not cool. Anyone else see anything like this? As well, with A/C on, you cannot turn up the heat and get heat in the cab. In the winter when the windows fog, I like to turn on A/C to defog the windows, but can't keep the heat coming out. Any thoughts?

Look for mice in the cab top. Seriously.

 

[Kioti Dave]

Look for mice in the cab top. Seriously.

Just had top off. Luckily, no mice. Had tractor out yesterday, and being able to run A/C with heat kept the windows clear. If you don't have kit yet to allow for this, it does help quite a bit. We did have a good dump of snow on weekend, about 8 inches. Winter is here.

 

[kioti617]

Thanks for the info. Contacted dealer, and the kit is on order and will be installed on warranty. If you use your tractor a lot in winter, you need to be able to turn on A/C with heat to keep windows clear.

I have a NX6010 (2019) and I have the same problem with the window condensation. I called the dealer and they picked up the tractor and performed some type of wiring upgrade however my A/C will not come on when it's cold outside so I still get the condensation. It seems like the temp needs to be around 25F or more for the A/C to come on. So when plowing snow on a cold day I still have the condensation problem. I'm considering buying a 12v fan with a cigarette plug to increase the air movement hoping that will help. Does your A/C work (light indicator) come on when it's colder than around 25F?

Thanks

 

[Kioti Dave]

I have a NX6010 (2019) and I have the same problem with the window condensation. I called the dealer and they picked up the tractor and performed some type of wiring upgrade however my A/C will not come on when it's cold outside so I still get the condensation. It seems like the temp needs to be around 25F or more for the A/C to come on. So when plowing snow on a cold day I still have the condensation problem. I'm considering buying a 12v fan with a cigarette plug to increase the air movement hoping that will help. Does your A/C work (light indicator) come on when it's colder than around 25F?

Thanks

It seems there is a temperature sensor in cab roof. Until temp in roof rises to a certain temperature, the A/C will not turn on. This is to protect the system. After the engine warms up, and the sensor gets to the proper temperature, the A/C will then turn on. Sometimes this takes 20 minutes or so. Run heater at max to warm the roof area up quickly. I also have a 12v fan to keep rear window clear.

 

[Threepoint]

Kioti617, here is a post I made last month in another thread that might be helpful:

Attached is a description of the "Thermocon" operation in the NX HVAC system. If I'm interpreting it correctly, the thermistor's set point is nominally 32 F. So, if it senses an ambient temp in the roof cap below that, the AC relay will not switch on. Does that sound right?



Since some are reporting no illumination of the AC indicator light prior to warm up, the light evidently is wired between the thermistor and the AC relay, thus will not illuminate below 32 F. That seems a bit odd, though, as more logically I would expect it to illuminate whenever there is power to the thermistor. Then, as the roof cap temp reaches the set point, the thermistor would allow current to flow to the AC relay, while the light stays lit the entire time until the AC switch is toggled off.

But, then, I'm no electrical design engineer, so I may be all wet on all of this.

 

[kioti617]

Thank you for your reply and very helpful information. I guess I will pick up a 12V fan to help the air movement. We have had weather cold enough that the sensor has not warmed enough even after 30-45 min of operating time with the heat full blast. Others stated that 12V fan did help.

I do truly enjoy the tractor and it saves on this aging body