I have two lawn tractors, both have Kohler Command Twins, one a 23 horse, the other is a 18.
The 23 horse unit charges fine. Voltage while running hovers right at 14.0V, when I shut the mower down the battery is usually around 12.8V (maybe a bit higher until the surface charge wears off).
On the 18 horse, it either isn't charging or not charging well. I can't recall the battery being drained completely (I usually hook the charger to it occasionally to prevent that), but it does not behave like the other mower. Voltage while running is usually 12.75 volts or so, and when I shut the mower down battery settles in at 12.5. If I hook a charger to it, the battery will accept plenty more charge, so evidently it's not being charged fully. This particular mower has an ammeter, and when the PTO is engaged or headlights on, the needle reads in the negative (discharge) side of the gauge. If both PTO and lights are on, it's substantially in the negative side. If the mower is just idling at high RPM, the gauge will rest just a hair into the positive.
Just for grins, I swapped what looks like a bridge rectifier (mounted on side of block and has three prongs: AC, AC and B+) between the two mowers. No change.
Any ideas how to go about diagnosing this?
The 23 horse unit charges fine. Voltage while running hovers right at 14.0V, when I shut the mower down the battery is usually around 12.8V (maybe a bit higher until the surface charge wears off).
On the 18 horse, it either isn't charging or not charging well. I can't recall the battery being drained completely (I usually hook the charger to it occasionally to prevent that), but it does not behave like the other mower. Voltage while running is usually 12.75 volts or so, and when I shut the mower down battery settles in at 12.5. If I hook a charger to it, the battery will accept plenty more charge, so evidently it's not being charged fully. This particular mower has an ammeter, and when the PTO is engaged or headlights on, the needle reads in the negative (discharge) side of the gauge. If both PTO and lights are on, it's substantially in the negative side. If the mower is just idling at high RPM, the gauge will rest just a hair into the positive.
Just for grins, I swapped what looks like a bridge rectifier (mounted on side of block and has three prongs: AC, AC and B+) between the two mowers. No change.
Any ideas how to go about diagnosing this?