New DK5310SE cab; A/C inop ... thoughts?

[AirOpsMgr]

Howdy y'all, I have about 70hrs on my new DK5310SE HST cab model, the cab a/c was working great up until a couple of days ago & wanted to post this question in case I'm missing something before I take it back to the dealer.

Long story short, a/c quit blowing cold air, dealer says to bring it in on Monday and they will see what's going on, but wanted to see if I missed something obvious before trailering it 55 miles and letting it sit until they diagnose / order & receive parts and fix.

As for the details, in the immortal words of Paul Harvey, Now, for the rest of the story......


I was out mowing grass (was about 80° out), ran it for 2.5 hrs, a/c was blowing nice and cold and the a/c fan was set on low. I took a break to help my wife with a few things, parked the tractor, let it idle for about 6-7 minutes and as it was cooling down, I noticed a slight "burning" smell, almost as if the tractor was in ReGen, which I have been through twice now ... due to smelling it, I checked the air vents, only a little debris, wiped them off and popped the hood to check the radiators.

When I popped the hood, the smell seemed to dissipate and so I let the tractor idle to make sure it cooled snd went ahead and checked the radiators; not seeing much in the radiators / screens, I went ahead and shut it down to check everything out and blow out the radiators & pull the screen anyway.

Not much there, used a compressed air wand to get in between the radiators, blowing in both directions just to be sure, almost nothing on the removable screen, so I looked at the belts, all good and had tension. Turned the tractor back on and the belt is turning the compressor.

Turned it back off, and for kicks & giggles, checked the fuse box - the 25amp a/c fuse was good.

I came back to it after it was fully cooled and went ahead and finished the last portion of mowing; While doing so, tried the a/c in different settings and fan speeds, but no dice, a/c light comes on when pressing the a/c button, fan blows correctly on each setting, but no cold air.

After parking it and coming back to it a few hours later to check again, still nothing; did a radiators rinse-out with a hose / wand, making sure to get in-between each radiator and while a little debris came out, not much ... I ran it again later that evening when the engine was cold and still nothing.

So at this point, I've reached my shade-tree MX capabilities, I don't own a/c test gauges and such, so I called the dealer the next day. The dealer's MX Mgr says they're backed up, short a mechanic, can't send a mobile tech, but if I bring it this Mon, they should get to it soon, but depending on cause / parts needed, it may be there a while.

So ... anything else I should check? Or, have I done as much as I can and just need to suck it up, tow & drop and hope for a quick turnaround?

Much obliged for any other suggestions.

Best regards,
Greg

 

[Harry in Ky]

If it's a warranty issue, I wouldn't suggest you should fix it yourself, but if you're looking for something to check, start with the compressor belt, and clutch assembly. Is the belt tight enough to run? Does it look like it's been slipping? Do you see any signs of scorched paint on or around the clutch and pulley assembly? Your description could easily apply to a problem in that area.

 

[Tinhack]

Turned the tractor back on and the belt is turning the compressor.

Are you sure? Or is the belt just turning the pulley. There's an electric clutch that engages the pulley to the compressor. That clutch is controlled by the unit inside the cab. Check to make sure the clutch wire didn't get disconnected by high grass/weeds.

Edit: Forgot to mention: A low charge will also disable the compressor clutch.

 

[BCLoco]

Like Harry said, there's not a lot of things you can do on this system if it's under warranty, especially if you don't have the tools. And like Tinhack said, the if it's a clutch-style compressor, you need to see if the clutch (the center part of the compressor pulley) is turning. That is what tells you if the control module thinks everything is fine. If it sees a problem, it's first response in almost every case is to disable the compressor clutch to save the system.

My guess? Either a misrouted wiring harness finally melted through on something hot, or something poked a hole in one of your A/C components, and you lost your refrigerant. Not sure if Kioti is still using R134a in their HVAC systems, or if they've moved to R1234yf like the automotive world has. R134a has a smell that is not that different from the regen smell, to my nose anyway. Not sure what R1234yf smells like yet, but I'd guess maybe like canned beans because that's all you'll be eating for a while if you have to pay for an entire system of that stuff. Holy mackerel it's expensive.

I really hope it's a misrouted wiring harness, because the dealer should be able to patch that up quickly for you, and at no cost. Good luck, and keep us posted.

 

[AirOpsMgr]

Thanks everyone, great info and thanks for the clarification; I should have said that the pulley is turning as I don't know if the compressor is engaged.

I've checked most of the accessible wiring and tubing and not found anything odd yet, but that's not much since I haven't tried to disengage the back of the hood to give better access toward the aft section of the engine.

I'll take another look, but sounds like a job for the dealer at this point.

Thanks again!

Best regards,
Greg

 

[LouNY]

To see if your AC compressor clutch is working, have someone turn the AC on and Off in the cab while you are watching the compressor. Or with the door open at a low idle turn the AC on and off you should be able to see and hear a change in the engine if the compressor is kicking in.

 

[AirOpsMgr]

To see if your AC compressor clutch is working, have someone turn the AC on and Off in the cab while you are watching the compressor. Or with the door open at a low idle turn the AC on and off you should be able to see and hear a change in the engine if the compressor is kicking in.

Roger that, I will do that. Thanks!

 

[Venturabass]

I know you said you blew out the radiator but there must be a separate condenser core for the AC. Did anything blow out of the radiator? In case you didn’t blow out every one of those multiple radiator cores under the hood.

Interesting thoughts from others on loosing all the refrigerant. You could locate and follow all lines to see if there any signs of a leak. In vehicles there’s usually a lubricating oil so I’d think youd see signs of that at a leak site.

I’ve got a DK5310SE but ROPS model. I have the factory repair manual. If I can be any help and send you images of anything on the AC system, send me a PM.

 

[toxicjeeper]

Would the dk5310 manual be similiar to the ns 5310 manual? I have been looking for a copy since I bought my tractor.

 

[AirOpsMgr]

Thanks again for all the help & suggestions; I trailered it back to the dealer today for them to diagnose & address under warranty.

First impression from one of the techs is something melted near the condenser pulley as he pointed out what looked like a spray pattern on the underside of the hood, which looked like black melted plastic residue that spun off of the condenser pulley or in that general area (I thought it was just dirt/grime & totally missed it).

Will update when I learn more.

Best regards,
Greg

 

[Harry in Ky]

It seems I mentioned you should look at that area back at the beginning of all this.

 

[AirOpsMgr]

It seems I mentioned you should look at that area back at the beginning of all this.

Yes, it's indeed my fault for not being more thorough

 

[Midniteoyl]

It doesnt matter. Its a warranty issue either way.

 

[Threepoint]

Yes, it's indeed my fault for not being more thorough

Greg, I hope you're saying this tongue-in-cheek! Your troubleshooting steps were pretty thorough, IMO.

Let us know what the tech ultimately finds. Thanks for the write-up.

 

[AirOpsMgr]

Greg, I hope you're saying this tongue-in-cheek! Your troubleshooting steps were pretty thorough, IMO.

Let us know what the tech ultimately finds. Thanks for the write-up.

Nothing definitive yet, called the dealer this AM for a progress report; The mechanic working on it wasn't there, but the office Mgr said he knows there is a compressor on order for it along with some other parts and would have the tech give me an update next week.

Will update when I hear more.

Brgds,
Greg

 

[AirOpsMgr]

I spoke with the dealer this past Fri to get a status report, the tech said "All the parts came in yesterday and we should have you ready to go mid-next week", to which I asked, "So what ended up being the root cause?" He responded, "We usually just order all of the parts needed, won't really know until we start digging into it, but most likely the compressor seized"

Will update when I hear more Wed of this week; hopefully she'll be ready to come home and get back to work ... mowing 15 acres of grass over the past 2 days on a 72" ZRT already has me missing that A/C'ed cab!!!

 

[AirOpsMgr]

Picked my tractor up from the shop today, Mechanic said it was a seized compressor / burnt clutch; He also said he's done 5 of them in the past year at varying hours, but mine (at 70 hrs) was the lowest he's seen.

He said once replaced, he hasn't had any come back, but doesn't know what's causing the initial fail. They ran it for 2 hrs yesterday with the a/c on full without issues; I'm about to get some seat time to catch up on 3 weeks without it, fingers crossed!

 

[Midniteoyl]

Bad batch, it happens. As long as they take care of it, all's good.

 

[AirOpsMgr]

Bad batch, it happens. As long as they take care of it, all's good.

Indeed, $0 out of pocket due to warranty, so all good with the exception of being without for the past 3 weeks. On a good note, 5 hrs of seat time this afternoon and the A/C is still nice & frigid .... for now.

Speaking of bad batches, i'll digress just for a moment to say that part of my career has included some dealings with Ground Support Equipment (GSE) maintenance of airport ramp equipment, used to load and unload aircraft.

Just within the past year, we've encountered a bad batch (or consecutive bad batches) of alternators from several vendors across the US, some failing within a couple of days, but nearly all within a month. We think we've narrowed it down to a couple of primary part numbers that are resold by others within the market, but only time will tell.

And FWIW, none of this is meant in a derogatory tone toward Kioti or the local dealer; I've seen top-tier items fail in many applications and know that all colors are susceptible, just wish my case wasn't 3 weeks of downtime (which was mostly caused by short staffing of MX techs at my dealer).

I'll update further as I get more hrs on the meter.

Brgds,
Greg

 

[AirOpsMgr]

Quick update, after getting the A/C compressor replaced at about 70hrs, the 2nd unit went out at about 90ish hours (this time the clutch was engaging and disengaging when the A/C was turned off and on, however, it would not produce cold air); Similar to the first occurrence, there was melted plastic blown off onto the underside of the hood - belt and pulley were intact, not sure where the melted plastic spun off of other than the pulley.

Dealer replaced it again under warranty and stated that they spoke with Kioti but have no further info as to why it failed again.

I'm now on my 3rd A/C compressor, so far have put about 12hrs on this one and no issues yet (all 12hrs have been using a finish mower at full PTO RPMs in the mid-90's outdoor temp, but I'm taking breaks every couple of hrs (as I did before) to ensure the hood screen vents are clear and every 4 or 5 hrs I blow out the radiators just to be safe. No major buildup just as before, but will continue the practice to keep that ruled out.

Would be interested to hear if any other Kioti owners are having issues with A/C compressors on new units.

Brgds,