Save This Page ] [ Follow Ups ] [ Post Followup ] [ John Deere Tractor Discussion Forum ] [ FAQ ] Save This Page ] [ Follow Ups ] [ Post Followup ] [ John Deere Tractor Discussion Forum ] [ FAQ ]
| | SSB Farm Tractor Parts, Manuals & Antique Tractors | | Aftermarket Tractor Parts | | Tractor Service & Repair Shop Manuals | |
| | Tractor Implements | | Tractor Seats | | Trailer Parts | | Tractor Loaders | | PTO Generators | | Rear View Backup Camera | |
| | Pedal Toy Tractors | | Tractor Books | | Antique Farm Tractors Blog | | Antique Tractors History | | Rustic Home | |
In Reply to: 318 will not charge. posted by Gary on Sunday, July 18, 2004:
Gary - There are a few things you can check.
First off, make sure the wire connections at the ignition swtich and PTO switch are free of any corrosion and are good an tight.
Next, check the main ground (usually located behind the battery on the back of the pedestal). Make sure there's no rust or paint in the area of the ground point.
Then, make sure the battery and starter connections are clean.
If you still are having problems. . .
The "Low Battery" light comes on when the voltage to the battery drops below 12.3 volts DC. Set a digital voltmeter to read DC and at full idle, check the voltage at the battery. You should get a reading over 13.5 volts DC up to 14/14.5 volts DC.
Next, locate the voltage regulator/rectifier. It's located on the right black engine shroud. With the ignition key off, remove the wire at the middle terminal. Start the tractor, and at full idle touch the ground probe from a digital voltmeter to the engine block and the positive probe to the middle terminal of the regulator. You should get a reading of 13.5 - 14.5 volts DC.
If not, turn engine "off". Replug the lead to the middle terminal. Unplug the outer two stator wires from the voltage regulator. Turn engine "on". Set the digital voltmeter to read AC volts. At full idle, contact one probe from the digital volt meter to one lead, the other probe to the second lead. The reading should be at least 28 volts AC up to 57 volts AC.
If the voltage from the stator leads is within spec and the voltage from the middle regulator terminal is not, it's most likely the voltage regulator has been fried. But there are a few more tests to do to make sure.
Next you need to make sure neither stator lead has any continuity to ground with the key in the "off" position. If any continuity registers, you'll need to replace the stator.
Finally, you need to check the resistance of the stator leads, again with the key in the "off" position. Connect an ohmmeter to the stator leads. The resistance should fall between 0.10 to 0.19 ohms.
If the voltage regulator does not check out, and the stator does, then replace the voltage regulator.
If the voltage regulator does not check out, and the stator does not check out, then replace the stator, and recheck the regulator.
Good luck. - Dave