You'll need an inexpensive digital voltmeter to test the system. Start by charging the battery for a half hour or longer on slow charge. Measure the voltage after removing the charger. If it reads near 12.6 volts, the engine should start and stay running. If it doesn't, suspect dirty / corroded battery cables. A common problem on Fords is a corroded cable under the insulation of the cable that attaches to the starter.
If the engine keeps running with the charged battery, measure again while it's running. It must be between 13.75 and 14.75 volts. If it's low, we need to test the voltage on the yellow and green / red wires on the back of the generator. The yellow one must have 12 volts all the time. If not, check for a blown blue 15 amp fuse.
Friday, December 3rd, 2010 AT 6:49 PM