# JD 5205 Location of Advanced Fuel Sensor



## Charles W Florence (Aug 22, 2020)

I have a John Deere 5205 year 2000 . The RPMs dropped while mowing . I checked the fuses for the fuel solenoid and it was blown. I have read information that this is possibly caused by a bad Advanced Fuel Sensor and to disconnect it and if the fuse stopped blowing this was the problem. I have also been told this by my J. D. Dealer tech. I am told that it is located on the thermostat housing . I cannot find it. Could anyone please help me . where is it in the housing? Is it possible that my tractor does not have an Advanced fuel sensor? It was manufactured in August , Ga.in July of 2000.

Thanks . Charles W. Florence Forsyth, Ga


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## Fedup (Feb 25, 2014)

So did it blow the second fuse? Look at the injection pump wiring. There is a wire at the top of the pump for the shut off solenoid. Also should be one to another solenoid near the bottom of the pump. This one is the start advance mechanism. Both wires lead into a harness. On that same harness is another lead going to the temp sensor you're after. It's the one with a two wire pigtail, not a single wire. Maybe it's already been removed and left out of the system. Many have.


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## Charles W Florence (Aug 22, 2020)

Fedup said:


> So did it blow the second fuse? Look at the injection pump wiring. There is a wire at the top of the pump for the shut off solenoid. Also should be one to another solenoid near the bottom of the pump. This one is the start advance mechanism. Both wires lead into a harness. On that same harness is another lead going to the temp sensor you're after. It's the one with a two wire pigtail, not a single wire. Maybe it's already been removed and left out of the system. Many have.


Thanks so much for your response. It did blow the second fuse. I bought the tractor new so I don't believe the sensor could have been removed. I can not find the sensor on the thermostat housing. I can find only one electric wire at the top of the pump that goes to the ignition switch. 

When the tractor is started it immediately blows the fuse but will continue to run at 1600rphs. The rpm will not go above 1900. It does this after running about 15 min. I have checked the continuity of the fuse and the wire attached to the top of the pump and it is good. I replaced the fuse and turned on the switch, the meter registered only .02 volts.(I did not engage the starter) Should it register 12 v? I have used all my 20amp fuses so I put in a 30amp on order to check this voltage, then removed the 30amp fuse and it was HOT. I have seen on one of the blogs that the pump could be connected to the battery with a toggle switch to by pass the wiring to the ignition switch. 
Thanks again. I appreciate it. Charles W Florence


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## Charles W Florence (Aug 22, 2020)

Charles W Florence said:


> Thanks so much for your response. It did blow the second fuse. I bought the tractor new so I don't believe the sensor could have been removed. I can not find the sensor on the thermostat housing. I can find only one electric wire at the top of the pump that goes to the ignition switch.
> 
> When the tractor is started it immediately blows the fuse but will continue to run at 1600rphs. The rpm will not go above 1900. It does this after running about 15 min. I have checked the continuity of the fuse and the wire attached to the top of the pump and it is good. I replaced the fuse and turned on the switch, the meter registered only .02 volts.(I did not engage the starter) Should it register 12 v? I have used all my 20amp fuses so I put in a 30amp on order to check this voltage, then removed the 30amp fuse and it was HOT. I have seen on one of the blogs that the pump could be connected to the battery with a toggle switch to by pass the wiring to the ignition switch.
> Thanks again. I appreciate it. Charles W Florence


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## Fedup (Feb 25, 2014)

It's true that many tractors have been modified as you described with a separate switch/circuit to bypass the fused circuit. Usually it's because those involved either didn't understand the circuit, or felt adding another switch and wire was easier than simply unplugging the temp sensor. It does indeed work. 

Whenever I've run across this issue I've always been able to follow the harness up from the pump and forward to the sensor. Whether it was always in the thermostat housing or not I don't recall.


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## Charles W Florence (Aug 22, 2020)

Fedpu. Thanks again for your response. The reason I have not just disconnected the sensor is that I cannot locate a sensor on this tractor that I bought new in 2000 . Also the only wires I can find on the pump is the wire that comes from the ignition. 

I did wire the pump directly to the battery. The tractor started right up and would advance to max rpms. (it would not advance but to 1500rpms before and would blow the solenoid fuse)I started to throttle it back and it shut off. I noticed the the bolt just below the hot wire ignition bolt was smoking ,a lot, I immediately turned off the switch.I tried to start the engine again and it would not start. Is it fair to say that the capacitor switch on the inside of the pump on the top, just below the hot bolt connection possibly has been the cause of this problem? I think I might could replace the capacitor myself. You option on this is greatly appreciated.


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## Charles W Florence (Aug 22, 2020)

I may I have the problem solved. With some research I have found the the cold start advanced sensor is an option . I have decided to get a new solenoid for the pump. I hope this will solve the problem. I speculate that the old one is bad and shorted out blowing the fuses. Note: I have been calling the shut off solenoid a capacitor , which is not the used name. I will report latter on the disposition of the situation . Thanks to all.


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## Tx Jim (Jul 28, 2020)

Charles W Florence said:


> I may I have the problem solved. With some research I have found the the cold start advanced sensor is an option . Thanks to all.


It's odd that viewing 5105 parts catalog reveals no cold start sensor option or serial # breaks for no CS sensor.


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## Charles W Florence (Aug 22, 2020)

Yes after calls to John Deere dealers, four exactly , three reported that the Advanced fuel sensor was standard and not an option.John Deere Corporate told me they do not have a technical support Department and I must call a dealer for this service. I had read in the forum on this problem of fuses blowing that two people had posted that their 5205 did not have a sensor. That prompted me to ask several times if my tractor might possible not have a sensor as I bought the tractor new in 2000.The last person I talked with in parts told me that it was an option according to his research . (he put me on hold so he could check). 

The pump requires a Torx Plus secure , 5 star, to take the pump off. T-25. One must be very carful replacing the solenoid and not put it in while not in the retracted position because it will be on the wrong Side of the governor , I'm told, which could cause the ungoverned engine to run away. 

cwf


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## Tx Jim (Jul 28, 2020)

I located a plug to utilize in lieu of sensor but there's no serial # break listed.


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## Charles W Florence (Aug 22, 2020)

27Sept2020 New Flag German made solenoid switch installed . Installing the solenoid sd be done very carefully . I made a wire with clamps to ground the pump top . I turned on the switch and attached the grid clamp to the strap that connects one post of the solenoid to the cast aluminum top. I turned on the witch and attached the grid cable , the solenoid retracted. , I then placed the top on the pump and tightened it down . I then turned off the ignition switch. (no sound was heard) This is very important if the solenoid is not retracted and put in place this will allow the engine to "run way" because the solenoid is not in the correct position. I fell pretty good having fixed this , one of life's small victories.Ha


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## Tx Jim (Jul 28, 2020)

Incorrect operating fuel solenoid won't allow engine to "run away" but just causes engine to be a little more difficult to stop running IE causing one to to have to manually stop fuel flow to IP or block air flow to air intake to stop engine


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## thepumpguysc (Jan 25, 2015)

Hey Jim, u haven’t been around Darrell & his other brother Darrell after they took the top cover off & jammed it back down.. instead of sliding it on.. The arm will lock the mv wide open.. lol


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## Tx Jim (Jul 28, 2020)

thepumpguysc said:


> Hey Jim, u haven’t been around Darrell & his other brother Darrell after they took the top cover off & jammed it back down.. instead of sliding it on.. The arm will lock the mv wide open.. lol


NO I don't know Darrell or Darrell!!! BTW Thanks for correcting my incorrect statement!


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