Start by measuring battery voltage with an inexpensive digital voltmeter. If it is fully charged, it will read near 12.6 volts. If you find around 12.0 volts it is good but discharged. Suspect the generator. If you find closer to 11.0 volts, suspect a defective battery.
If the battery appears to be okay, it will crank the engine without needing jumper cables after it has been charged for an hour at a slow rate. Measure the battery voltage again while the engine is running. It must be between 13.75 and 14.75 volts. If it is low, we have more testing to do first, but suspect a defective generator.
Monday, May 2nd, 2011 AT 4:19 PM