JD 3720 cab fan troubleshooting

[marshallcro]

If someone could please tell me if you fixed the blower motor fan on a JD 3720 cab mod. The fan stopped running, I changed the 20A fuse and it opened again. The items on the fuse list are : Dome light (that I don't have), radio/blower switch/RH Blower ( I don't know what the RH stand for , right hand?) Where is the fan located? Thanks in advance.

 

[kennyd]

There are two fans in the roof, you have to remove it to get to them. There are 13 bolts to remove, then it just lifts off-help is recommended.

RH is right hand, so that is the one that need to be tested. If the LH fan fuse is good and it’s not running, then it’s possible the control is bad.

 

[marshallcro]

Thanks a lot, I guess I have to remove the head liner of the cab to get to the screws to the roof. Do you know about removing the head liner any tricks for that? I'll try the control switch first , I guess the panel just pulls out with all the controls or is there a trick for removing that. The LH fuse is good so ill start there first cause I cant remove the roof until the weather warms up, machine is outside and ill have to put it under a temporary shelter. Thanks again.

 

[kennyd]

You need to remove the roof, not the headliner. Look around the underside edge of the roof, you’ll see the 13 bolts (actually they are just nuts now that I think about it) to remove.

 

[kennyd]

Here is a drawing, I was mobile earlier and couldn't get it for you. If you search for some of the radio install threads you probably find more info and pictures.

The red circles are where the fans live.

 

[PCABE5]

You need to remove the roof, not the headliner. Look around the underside edge of the roof, you’ll see the 13 bolts (actually they are just nuts now that I think about it) to remove.

Wow that's a lot of nuts. You related to Gizmo??

I'd just get a new tractor if it took that much to get to the fans.

 

[marshallcro]

Thanks a lot Kennyd for the print and your help. The LH fuse is good and fan is not running. I do have a dome light. I hope I can get to this job soon. Im going to pull the control switch first and start there along with the dome light. Thanks again.

 

[marshallcro]

I replaced the control switch and that wasn't the problem. The original switch smelt funny and had a lot of black dirt around it so I took the chance and put in a new one. Do you know if one fan is for AC and the other is for heat or do they both push air for both. Can you tell me of a good place to order parts on line.

 

[kennyd]

They both run at the same time.

I use these guys for online parts:

Green Farm Parts -

 

[kennyd]

I just looked this up for you in the Technical Manual. There are four relays and two thermal fuses in the circuit as well.

 

[Scarborough]

Sorry I'm late to the chat. Water collects under my RH fan and freezes in cold weather. Burns out the resistor and blows the fuse. I've replaced the motors Twice for the same issue. Once do defrosted, if the blower works on high you can try a heater resistor from a Bobcat. John Deere does not sell the resistor seperate and the blower motor is expensive. I drilled a hole in the base tray to prevent water from collecting under the fan again.