JD 5205 Schematic Are there more than oner/

RafterP · Jun 5, 2013

I have an electrical problem with my JD 5205. Turn on thh key and it blows the 30 amp fuse feeding the switch.
I downloaded a service manual, which has a schematic, but none of the wire numbers or colors match what I find on the tractor.
I have unpluged all connections (seat switch, key switch, PTO switch, neutral switch, dash connections, accessory relay & fuel cut off relay) so I should just be checking wires, according to the schematic. But I get solid continuity to ground on one seat switch wire. According to the schematic, the hot goes from key switch to seat switch to PTO switch, but I have no continuity between the seat switch wires and the PTO switch wires.
My conclusion is that the schematic I am using is different than my tractor is wired.
The manual lists two different fuse layouts, one early model one later model, and I have the later model layout, but the service manual only shows one schematic.
Is there another schematic for late models and how can I get one?
The John Deere web site lists the same publication I already have.

Thanks for listening. Any insights would be appreciated.

JD5210 · Jun 5, 2013

What does your manual say the 30 amp fuse is for?

I believe the problem is the thermistor sensor (thermistors are temperature variable resistors used as sensors.). On the thermostat housing there is a sensor that is connected to a two wire harness that goes to the injection pump; this is the "cold start advance" portion of the system so it starts easier when cold by advancing the timing.

When the sensor on the thermostat housing fails it shorts out and blows the fuse. Try unplugging it, replace fuse and see if it starts and runs. The part # is RE503242, if you are quick changing it, you don't have to drain the coolant, just make sure it's not hot at the time. You will want a pan under the tractor to catch the coolant, so as not too have to clean it up.

To comply with the exhaust emissions regulation, the timing of injection pump should be around 6 to 9 degrees before TDC. These timing values do not allow proper start-up operations when engine is cold. To ease engine start-up, a cold advance system gives to the injection pump a temporary over-timing.

When coolant temperature is below 50 C (122 F), the solenoid valve is activated and opens the cold advance circuit.

URL to JD parts
jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

URL on the 3029 engine and addresses the cold start
www.visaevolution.com/dati_sito/manuali/officina/motori/john deere/ctm125-3029-ENG.pdf

5205 online manual
http://manuals.deere.com/omview/OMRE72817_19/?tM=FR