BigTuna
New member
Tractor is 8 years old with 900 hours on it and the battery died. Replaced with new battery and was OK for a few weeks and then dead again. I cleaned up battery cables and put on new battery terminal clamps which seemed to help, but after a week....dead battery. Frame is rusty where negative lead is welded so I installed a second negative lead (tapped framed and bolted) and I now have two negative leads attached to battery. That seemed to help for about a week as well....but now, dead battery! The problem has seemed to worsen over time to the point where I need more power to jump start than before; used to jumpstart with just jumper cables on truck, now I need jumper cables and a portable jumpstarter battery. I started to suspect the alternator and took some measurements:
Key off - 13 volts
Key on - 13 volts
Key start - 13 volts until you here a click (starter?) and then zero volts
Jump start and measure with jump cables still attached - 14 volts
Remove cables - 7 volts
If I turn the lights on the tractor dies. If I leave the tractor running it only runs for a short while and then dies.
It sure seems like an alternator problem to me, so I removed the alternator (belt was good and tight) to get it tested. Had my wife take it to the local guy that most local farmers use and he took one look at it and told her these never break! He said I should check all wires and the regulator. I already checked the wires and everything seemed OK. I'm not sure how to check the regulator, I think I read somewhere that you can disconnect and jumper around it to see if the voltage is higher than battery which would indicate the alternator is working, but I'm not sure how to bypass. At first I thought that the regulator not working would just not clamp the voltage from going over 14-15 volts and how could it keep it to 7 volts, but then I thought the regulator could have multiple diodes in series and if one of them was shorted it could be holding the voltage down to 7 volts.
Any thoughts on my next best step? Are these alternators truly that good?
Key off - 13 volts
Key on - 13 volts
Key start - 13 volts until you here a click (starter?) and then zero volts
Jump start and measure with jump cables still attached - 14 volts
Remove cables - 7 volts
If I turn the lights on the tractor dies. If I leave the tractor running it only runs for a short while and then dies.
It sure seems like an alternator problem to me, so I removed the alternator (belt was good and tight) to get it tested. Had my wife take it to the local guy that most local farmers use and he took one look at it and told her these never break! He said I should check all wires and the regulator. I already checked the wires and everything seemed OK. I'm not sure how to check the regulator, I think I read somewhere that you can disconnect and jumper around it to see if the voltage is higher than battery which would indicate the alternator is working, but I'm not sure how to bypass. At first I thought that the regulator not working would just not clamp the voltage from going over 14-15 volts and how could it keep it to 7 volts, but then I thought the regulator could have multiple diodes in series and if one of them was shorted it could be holding the voltage down to 7 volts.
Any thoughts on my next best step? Are these alternators truly that good?