3000 Series A/C Issues

[GreenMtns]

Well the "ole" catch 22. Contact John Deere and they will advise you to contact the dealer. I would suggest going to another dealer and trying another tractor like yours on a hot day. This would give you a reference point. I would then by pass the service department and talk to the manager/owner and explain to him that your unit is not performing like other units and ask that it be corrected.

I think Gator6x4 has the right idea. Check out another one at another dealers. I have run mine at 96 degrees and if the blower is on high I have to put a shirt on. Yours should be cooling as well. You might ask when the area rep will be around and speak with him. Something is wrong with yours since the rest of us are getting a lot more cooling than you are. Your dealer should want to find the problem as well. You have just spent a lot of money there and he should want you happy.
40 hours seems like a lot of time spent on it. That would equal one mechanic for a whole week on this and you still did not get cooling like you should have.

 

[ddivinia]

It sounds like time to write John Deere and ask for help. Get JD engineering involved or something. It sounds like your dealer is trying but doesn't have the expertise to work on it.

D.

 

[sunnyside360]

I have the exact same 3720 tractor and have felt the A/C is somewhat marginal on mine. Today I took some measurements with a digital meter with thermocouple which is pretty straight forward. Anyone having a 3x20 cab tractor can do this fairly quick if they are interested in this A/C issue. It would be good to know the same data for those that are happy with their A/C as well just for comparison and further understanding the issue.

1. Outside weather conditions -- cloudy and 86 deg F

2. Set A/C on MAX cold with de-icer ON and run for 10 mins at 1500 RPM

3. Air vent temps measured from 72 to 74 deg F (coldest when compressor on)

4. Cab temp at center of steering wheel varied from 78 to 80 deg F

As you can see the temp drop between the outside air and at the inside air vent is 12 to 14 deg F. This is an important figure when trying to determine if an A/C unit is functioning properly according to specification. In this case we do not know the spec but John Deere does. However, we can also compare data between tractors with A/C running well and those with A/C not running so well and use it as appropriate with dealer and/or John Deere.

Also did the plastic wrap test at air inlet as suggested above. With the fan on the lowest setting, there was enough negative pressure (vacuum) to suck the plastic wrap into the vent which hopefully discounts any other major air leaks.

 

[Silver_Knight]

I did some more testing today and here is what I found out:

1. Outside temp: 98 F

2. A/C set on coldest position with blower knob set on middle speed 1700-2200 RPM

3. Air vent temp measured from 70.5F to 72.5F

4. When blower speed increased to high vent temp would rise to 74-77F. A few minutes after decreasing speed of blower the vent temp would decrease to around 72.

Did the plastic wrap test and it sucked it in just fine. After running the shredder for an hour I got of and when I slammed the door shut I noticed a pretty big puff of dust come out of the back of the tractor where the filter is. Slammed it 5 more times and it puffed every time. Started the day with a new filter.

Did not notice much change in temp with RPM change.

Although I still do not believe the temps are great, or even good, especially on high, I guess I'll just keep the blower on medium and live with it.

 

[nmu98]

I just got my new cabbed 3720 last night. Took the top off to put in the radio.... 4 large holes in the sealer strip. Looks to be ripped. Mine sucked in the saran wrap too... but i could also feel the leaks before i took the top off....

 

[Labrat]

Take the thermocouple and zip tie it to the suction (large) line returning to the compressor. It would be good to insulate it and have it on the metal part of the line not the rubber part. Also, if you can get it close to the evap it would be better. The suction temp should be between 5 and 10 DEGF lower than supply air temp. If the delta is significantly higher than that you are probably bypassing evap air.

 

[sunnyside360]

I did some more testing today and here is what I found out:

1. Outside temp: 98 F

2. A/C set on coldest position with blower knob set on middle speed 1700-2200 RPM

3. Air vent temp measured from 70.5F to 72.5F

4. When blower speed increased to high vent temp would rise to 74-77F. A few minutes after decreasing speed of blower the vent temp would decrease to around 72.

Did the plastic wrap test and it sucked it in just fine. After running the shredder for an hour I got of and when I slammed the door shut I noticed a pretty big puff of dust come out of the back of the tractor where the filter is. Slammed it 5 more times and it puffed every time. Started the day with a new filter.

Did not notice much change in temp with RPM change.

Although I still do not believe the temps are great, or even good, especially on high, I guess I'll just keep the blower on medium and live with it.

Seems your A/C is working better than mine since you are getting around 26 to 28 deg temp drop between outside air (98) and inside air vents (70 to 72). I agree RPM's don't seem to make much difference. I'll try the "door slam" test and watch for dust cloud. I check/clean my filter quite often during summer months as a dirty filter will drop A/C efficiency.

 

[sunnyside360]

Although not much new to report I did the same measurements again this morning as suggested above.

1. Outside weather conditions -- sunny and 83 deg F

2. Set A/C on MAX cold with de-icer ON and fan on medium @ 1500 RPM

3. Air vent temps measured from 68 to 72 deg F - compressor on @ 72 & off @ 68.

I also slammed the door and watched for cloud of dust at rear and did not see any -- not surprised as filter was recently cleaned and haven't run in dusty conditions since.

 

[Nuru]

I am going in this morning and check out the seal, I am gonna take the top off first, and see what I can see. I am also exploring for a potential radio installation, but I have not decided on that yet. I am leaming towads portable or semi-portable SAT RADIO. SEMI Portable as in, installing an aftermarket radio/CD/DVD? combo with an auxlliray input, and use my small portable Sirius sportster and just plug it in when i want to run SAT Radio. i will post picks if I go with the new radio and auxillary input.

 

[nmu98]

Nuru, Watch the AC and heat control wires, and as you tighten the top down, make sure they work freely. One of them is help in place by a putty. My dealer warned me that that one likes to move to a place where it will bind if you dont watch it. I did not have that issue with mine, but i was very carefull to keep it in place.

My AC works like a champ with the new seal. I had to turn it off on an 85 degree day with sun. It was so cold in the cab I was getting a headache.