03 7.3 PSD
about 38,000 miles on the van
Last summer, I had both starting batteries replaced. One night, while camping, I discovered they weren't charging, so we coasted back down towards town, and, after a long tow and a delay in Durango, discovered that they were somewhat poorly hooked up. However, the alternator was also dead. Short story: bolts all tightened, and alternator replaced (standard alternator, not heavy duty, billed as a rebuilt).
All's been well 'til last week, on our most recent trip. The battery light on the dash comes on at any voltage output below about 12.5 - 12.7 volts. Once I rev the engine enough to bring up the volts, the light goes off. There are plenty of times in normal driving that the voltage output falls below 12.5, and the light will come on. As soon as the engine is turning faster, the light goes off.
Is this a problem? Is the dash "idiot light" set too high? Should the alternator be putting out more volts? Or is this a battery problem? The alternator should be under warranty, as are the starting batteries.
By the way, it never seems as though the batteries run down- so far the van has always started OK.
Any help appreciated!
'03 7.3 PSD
Salt Lake City