[trakman]

I posted this problem on another forum and got helpful ideas but nothing will fix it..so far.

In the heat of the day, at 100 degrees plus, the A/C system will shut down for about 20min out of every hour. Before you think that the high pressure switch is shutting it off, I've had a set of gauges hooked up for the last 4 days and when it's working, H/S has never been over 275...Low is down to around 25. It's not "freezing up" as the evaporator is clean and I don't run the thermostate more than 80% cold and run the blower on high and moving LOT'S of air. I washed the condensor, Hydraulic oil cooler and radiator so they are clean. Combine will not heat even in these temperatures. Freon level is adaquate according to a A/C mechanic that I had out to look at it 2 days ago. I replaced the $300 "air conditioning control module" (A/C system brain box) and that hasn't fixed the problem.

Ambient tremps of 100 and below and the system works fine. It's just in these hot afternoons that it fails and is really needed.

Might mention and I wouldn't think it would have anything to do with it but today on a 20 minute plus shutdown, had a bin full and was heading for the truck...shut the header off first and when I shut the separator off, at that very moment, it started to cool. If this is any indication of a problem, make me wonder if I don't have an electrical problem. Somtimes after it been cooling nicely, and you idle back to talk to the truck driver or someone, the system will shut down, but speed the engine back up and it's back to cooling.....like I'm short of voltage somewhere.

Any ideas?

Sorry for rambling on but this problem is not acceptable in my books, especially when it's hot....thats what A/C is for.

 

[farmboy1998]

Try and just replace the electrical wires and get some more heavy duty ones and it might work.

 

[homefarmtobydog]

Hi
We had the same problem on a 2388. We bought it as a demo done one year. Someone had at some time removed the cab filter and the unit under the seat was plugged with dust etc.

Dealer removeit and cleaned it all out .

Still the same real hot day and ac works when it wants to.

Lots of experts checked it out but never fixed it always working of course when they turned up.

Best of luck at least you know you are not the only one with this problem.

IF you get a fix please post it I would love to know even though we sold the combine.

 

[trakman]

Yesterday with the ambient temp not over 100, it only failed one time, and that was when the combine was at idle and I was talking to a landlord. Probably spent 10 minutes with him and when I got back in the cab, it was blowing warm air....BUT.....as soon as I throttled up, it went right back to cooling.

Still makes me think that it is a voltage or electrical problem. Parts man at Case-IH, after hearing how it acts said he thinks it is the compressor with a weak clutch. He said the Sanyo's compressors are notorious for weak clutch's, especially with a machine that has over 3k hours on it. He knew the machine before I bought it and is 99.9% sure that it has the originaal compressor on it. The previous owner passed away so can't ask.

Will probably change it out sometime as I'm going to put enough new stuff on it that at some point, it will be fixed!

 

[homefarmtobydog]

Defineatly the same problem. Some years I would think it was fixed but was just cooler so it kept working most of the time. 03 was really hot and it went off most days at 2pm and then on and off every half hour till about 7pm and then it would work fine till 2pm next day.

Ours was like this for ten years if it was a weak part wouldnt it have got worse or broke altogether. Most guys left saying when it stops working altogether we will come and fix it but it never did. Nobody wanted to replace parts they could see nothing wrong with on just a guess, and I am to tight to speed money without the promise of a fix.

 

[amax]

Hi
Did any one ever check the placemant of the evaporator temp sensor?

Amax

 

[trakman]

Sure did......was told by the AC mechanic that it was updated a few times as to the location.....he stuck it in the lastest bulliten position...didn't help.

Temp never got over 92 today and the AC worked as if it had NEVER had a problem.

 

[homefarmtobydog]

Drives you mad doesnt it. Pity you cant find out how long it has had the problem.

 

[trakman]

What gets me is this is the third wheat harvest that I have owned this machine...........and this is the HOTTEST harvest weather we'vd had of the 3 years......and the only year that I've had A/C problems. Like you mentioned, problem could have been there all along.

 

[brownie31]

I have a 2188 and a 2388 and the AC cuts out when it gets really hot our AC guy said to keep the fan on high because the condensor freezes up with lack of air movement. It seems to work for us , hope you get it fixed because a glass box and no AC really sucks.

 

[redhat]

Two things to check.
Make sure nothing is covering the recirulation foam intake area behind the operators seat (rags, coveralls , jacket, etc) and that the foam filter is clean.
Check the intake screen on the alternator by removing it from the intake tube and make sure it is clean. Will cause voltage regulator in alternator to overheat and malfunction. Will cause A/C controller, yield monitor, etc to not operate properly. Will only act up on a very hot day or when all the work lights are turned on. If you have a yield monitor in the combine you can bring up the voltage and see were it is running at, should be over 12.5 for things to work right

 

[caleb2684]

Just my two cents...

I have never worked on a combine ac but would imagine that your condensor coil is "stacked" with your hydraulic cooler and radiator all sharing the same air from the same fan. I dont know in what order the air passes through but if the condensor isnt first I can see your problem for sure. With the record heat this year head pressure has been killing all types of A/Cs. I do commercial and residential ac for a living and Im seeing it first hand. You say 275 head pressure, but is that in the heat of the day with the machine at full load with all functions on? I would assume your just measuring at the heat of the day during an idle break. Im not knocking you for that but I would bet that your problem is head pressure related. My first thing to tell you is wash the condensor coil daily! That sounds crazy but if you read what I said earlier it adds up and when the freon your sending in to the evaporator coil isnt subcooled properly it wont cool great and then will chain react and cause the head pressure to rise and then the head pressure switch to trip. As the freon circulates through the system naturally the pressure drops and the switch will reset and youre good to go. One way to check my theory is if you have access to a 1amp fuse and fuse holder. Wire it into the head pressure switch. One side of the fuse to one side of pressure switch the other to the other. When the pressure switch opens the current will try to go through the fuse and blow it. Then you know that at some point the switch is killing the compressor and your only cures are: 1. Lower your carbon footprint to prevent this global warming we have. Or 2. Wash your condensor daily to give it the best chance to fight these 105 days. Hope that this gives you something to go on. Also I was kidding about the global warming thing.

Caleb

 

[1680steve]

could be your compressor clutch starting to crap out on you, and thats why it engages when you rev it up but cuts out here and there at low idle. ....just an idea

 

[trakman]

Before next wheat harvest and hot weather, I'll probably replace the compressor and clutch. If ambient temperature is the deciding factor, I'm sure it will get throught Fall Harvest ok.

 

[casetech51]

I would try the preasure switches before replacing an expensive compressor and clutch. Personally, It sounds like the high preasure switch is kicking out prematurely. I dont remember the psi it is supposed to kick out at, but when I was turning wrenches I run into a new 2166 that would act the same, only difference was this was a fall machine. Turned out to be the low preasure switch was bad. Another tech had installed a replacement switch but had the same results. I took one from a Magnum tractor and adapted it to work on the combine and we never had a problem after that. Both switches had the same preasure specs but different suppliers. The switch is easy to replace and does not require evacuating the system. Good Luck.

 

[farmertony]

seems like I unhooked a switch under the buddy seat, on one along time ago, and fixed it.

 

[trakman]

Oh so many things to check.....ideally, I wished I had a set of gauge hoses that were long enough to hang on the railing outside the righthand door. Then at the moment it quit, I could see if I had a pressure spike and then most likely the high pressure switch kicks in and kills the system. I've purchased a high pressure switch ($99) and as some of you have suggested, will probably put it on first before spending $450 for a compressor. If the high side never gets above the 275 that I seen, then it makes me think that the switch is faulty.

 

[cboyd]

We were having a similar problem this year with our 2188, seems like it was doing it every now and again last year too. I checked the pressures a few times while it was runing in the afternoon heat and the high side was running around 250-260 and the low was around 25-30, so i let a little freon out till the high side was around 230-240 and havent had a problem since. Seems to be cooling alot better than before too, been having to turn the air down because its freezin me out of the cab. Seems the owners before us over filled the system by just a little bit.

 

[trakman]

The AC mechanic I had out told me that the system was just right on charge that day. Year ago, this system was "overcharged" by 3# and wouldn't cool very well. I had put a can or two in it thinking it needed it and actual I was creating a problem. I then went a bought some gauges and found out I was very high on the high side pressure (425) and the high side switch would kick in and shut the system down. Had this same AC mechanic out and he evacuated the system and brought it back to normal charge and it cooled just fine. This all took place after the wheat harvest of last summer and before fall harvest so ambient temps were much cooler.

Makes me wonder now if the high pressure switch didn't get damaged by the extreme pressure. Guess I should have changed it out during this wheat harvest.

 

[scott]

whats the air gap on clutch on compressor, can't exceed .015 inch, this can cause lots of weird things happen especially in extreme temps, takes to much current to pull clutch in, i beleive these compressors have shims behind face plate of clutch, takes special tools to remove and install, would like to know what air gap is, scott.