3720 JD cab with poor heat

[capp0021]

I recently received a new 3720 cab and at first the heat didn't work at all. I had to go out of town and the dealer came and did something but I don't know what as I was out of town and now with Christmas... Anyway, it works now but not well. It has been cold here, it was maybe 5 degrees the day I drove it around to test it. There was not much snow so I couldn't really work it other than drive down the street. As it is now, if you sat in the cab and it idled you would freeze to death. When driving it I got fair heat but not what I feel it should put out. The heat gauge came up over half an inch...as warm as my old 3720 without a cab would ever run even when working fairly hard. I sure wish they had numbers on the gauges. Anyone have any tips or ideas? I tried a cardboard in front of the radiator and if it helped it was only slightly.... I have found no posts from anyone having any similar issues.

I don't know if a different thermostat or hotter one would help? Maybe the fan could be removed? I really wish it would just work right...

Any help or ideas would be great, thanks!

Pat

 

[kuboman]

I would wonder of the valve that controls the flow of coolant to the heater core is not opening very much. Either that or the heater is really undersized.
How old is the machine?

 

[capp0021]

That's the thing....it's 5 days old! I may go to the dealer and go drive one around on the lot to compare to mine... They say they don't put out much heat unless you're working them, which is not much of an answer or solution.

 

[mjncad]

I'd bet the cab roof seal is damaged. I hear that is a common problem on cabbed Deere's.

 

[capp0021]

Yeah, I was just reading about that now...I couldn't find a pertinent post until I started mine! I did have a radio installed, but you would sure think they would know about this issue... Like I said earlier, I had NO heat at the start, so I wonder if they have been in the roof twice now...

I'm going to go talk to the dealer tomorrow...or today I guess, its pretty late here.

I don't know if anyone reading this has read the older post (from 2005-7), but I may be starting to get paranoid now, as this new tractor smokes and smells stronger than my 2005 3720 (without cab - that's why I got a new one!) also.

anyway, thanks - we 'll have to see and I will post results for the next guy with this issue.

 

[greg_g]

Mine had poor heat, which was fixed by a tech who'd apparently never worked on a 3720 cab before. It was indeed the heater core valve not opening fully, an issue remedied by a simple adjustment of the cable between the cab and the core. But he apparently thought he could remove the cab roof by himself. Either that, or he over-estimated his ability to lift the roof by himself. That mistake damaged the roof seal, and of course they didn't have a replacement in stock. The damaged areas were "fixed" with auto store weather seal. I'd already had previous issues with the selling dealer, and this was just one too many. I shifted my warranty work to another dealership.

//greg//

 

[Cigar Face]

Here's a recent thread about your issue and the fix
http://www.tractorbynet.com/forums/...ng/265483-obtaining-heat-inside-3320-cab.html

 

[sixdogs]

On things like this I have learned to start with the easiest answer first and work up from there so my guess is on the flow valve not fully opening. Remember that tractors take a long time to warm up when it's cold old and even a half hour at low air temps would likely barely do it. Low heat until things warm up.

 

[kuboman]

You will have a temp knob in the cab which adjusts the heat output by opening or closing a valve. This may be out of adjustment. Also on a lot of machines there are shut off valves in the heater lines at the engine. One or more of these may be mostly closed. Just some more options to check.

 

[sunnyside360]

I have a 2007 3720 which I bought new March 2007. The heater was anemic when new similar to yours. Turned out the roof seal was damaged and leaking cold outside air into the roof chamber. Heater worked fine after dealer replaced the seal. The roof had to be removed at the dealership to install the radio prior to delivery so the seal may have been damaged then but not sure. I found the problem by removing the roof to check items described by other posters above. Roof install/removal is definitely a 2 person job otherwise the seal is likely going to be damaged. Other popular causes of weak heat in the 3x20/4x20 cabs has been air trapped in system and heat valve adjustment as noted above. Your dealer should fix this issue under warranty.