JD 4420 cab wiring

[Paul swpa]

Lost power to the overhead console in the cab - no fan,(a.c.), windshield wiper, even radio. I haven't been able to find a schematic showing where the power originates from for testing things out. It looks like one power lead provides power up there but where from? Key switch, connection in engine compartment? Local Deere dealer wasn't any help. Didn't want to tear apart anything more than necessary to find where the problem is, like the side console if it doesn't come from key switch. Thank you, Paul

 

[Loosehandle]

Id be looking for mouse damage in top of cab

 

[Paul swpa]

That's what I originally thought. Took the top of cab off, no signs of mice up there. One did get into the seat in cab in last couple weeks. Had lot of chewed up foam to vac out. No other mouse signs.

 

[Paul swpa]

Might have found a downloadable manual. Anyone ever use external_link for manuals? Supposed to be out of Nevada, run by someone from Iowa.

 

[61-4010]

The JD website has some ok schematics that might help (https://partscatalog.deere.com/jdrc/navigation/equipment/67793/level/2/snp/MjMwOTcyMDpDSEFQVEVSWzEwNjE6I0JVU0lORVNTX1JFR0lPTiwyNzM2OiNDQVRBTE9HLDY3NzkzOkVRVUlQTUVOVF)

There are 3 circuit breakers for the cab roof and a 10 amp in the engine compartment for the cab accessories.

 

[Paul swpa]

Yes 61-4010, I had already seen that diagram in the parts list. Doesn't give me quite what I'm looking for. I have isolated the power feed wire going to cab overhead and it has continuity so think it is ok. However It doesn't seem to be getting power to that wire so I have to find out what feeds the power to it which isn't shown on the parts list diagrams. Thank you, Paul

 

[61-4010]

If I'm following along, you are getting continuity but no power. So if so, there is a 10 amp circuit breaker in the engine compartment that controls can accessories. In the engine compartment (right side) there is a metal plate with 4 circuit breakers. Upper right is the 10amp for the cab accessories. Perhaps test that breaker and/or the power lead to it.

Sorry if I misunderstood or if you've done this already.

 

[Paul swpa]

Pretty sure I've got the power issue fixed. The power feed to the overhead console in the cab comes from a relay in the engine compartment (back left corner behind the fuse block). I was having trouble seeing what fed this relay. Turns out it comes from a block (believe it is a solenoid) on the firewall. Ran some jumper wires while I had a meter connected. At first the relay would just hum, then it started to click like it was actuating, now it works as it should. Apparently it was stuck and giving it a good shot of full voltage got it working again. I was jumpering between the power in feed line and the activating line , which I still haven't found where it comes from but would assume it is from the ignition switch in cab. Thank you, Paul

 

[Mattbowen61990]

Pretty sure I've got the power issue fixed. The power feed to the overhead console in the cab comes from a relay in the engine compartment (back left corner behind the fuse block). I was having trouble seeing what fed this relay. Turns out it comes from a block (believe it is a solenoid) on the firewall. Ran some jumper wires while I had a meter connected. At first the relay would just hum, then it started to click like it was actuating, now it works as it should. Apparently it was stuck and giving it a good shot of full voltage got it working again. I was jumpering between the power in feed line and the activating line , which I still haven't found where it comes from but would assume it is from the ignition switch in cab. Thank you, Paul

Hey Paul, That wire is fed directly from that relay. There are 4 wires on that relay, one ground, one hot wire (Thicker wire, connects to the starter relay right beside the cab power relay), one wire from the fuse block powered by the key (Small Green wire), and the thicker red wire that goes to the cab fuse block up top of the cab.
I had to replace that relay last week on mine. Don't go to Deere for it($100+), look for a 4 post relay on Amazon for $10 and replace it.