jd x748 fuel solenoid and alt questions

deene · Sep 14, 2015

i have posted this before in the garden tractor section and thought I would try here also..i recently purchased an x748 and..i need to know what voltages the fuel shutoff operates at..it is a 3 wire system coming from a relay under the dash..one 12guage wire shows 12 volts when key is on,,the 16 guage wire to it shows .43 volts.. and then the ground ..the solenoid gets hot and so do the 12 ga wires when key is left on for about 30 or 40 seconds..does it reduce the voltage somehow when started?..also the alt doesn't charge..its a pancake style alt to describe it the easiest and it is a 2 wire plug in..what excites it to begin charging..thanks for any inputs or thought on this

tirekicker · Sep 14, 2015

Hi, On your fuel shutoff solenoid, the white heavy wire is for the pull in coil inside the solenoid, the small power wire is for the hold in coil, and the third wire is ground. Both voltages are 12 volts dc. The pull in coil pulls in the solenoid, after a brief time the hold in coil is energized and the pull in coil is de-energized. The dash panel controls this. The alternator self excites and the way to test it is to unplug it and measure AC volts. It should put out a minimum of 40 volts AC at fast idle. The voltage regulator converts this to dc. Hope this helps.

deene · Sep 14, 2015

dash panel is not doing this what is the run voltage on the secondary coil?..i tested dc output on the 2 poles on the alt and got nothing so will try ac setting on the meter..thanks for your response

tirekicker · Sep 15, 2015

Hi,
Both the pull in coil and the hold in coil inside the shutoff solenoid operate at 12 volts.

jd x748 fuel solenoid and alt questions

deene

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deene

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