Alternator voltage

[Bwana Bob]

My rebuilt replacement alternator does the same

Before that though with the stock alternator showed 14 constantly since I bought the truck used. Finally the stock one died ant only could give out 12 volts. Service tech said that voltage was supposed to change with demand and not run at 14 constant.

Mine does the same thing! The original alternator ran about 14.5 V consistently. It wore out at 200,000+ miles so I replaced it with a rebuilt one. The rebuilt runs at aabout 14.2 when cold and it drops to about 13.5 when hot. It worries me a little, but I guess its normal. Is there some temperature compensation in the regulator to keep it from overcharging a hot battery or does it just drift with temperature? My original alternator did not do this, but the early Explorers also would boil off a lot of acid with the original Motorcraft battery. Ford's solution for the '91's was to install a plastic cover over the battery so that the acid wouldn't eat up the wires!

Bob

 

[X-North]

Anyway ford sucked in electrical diagrams so maybe they changed the setting of diodes trio i the alternator due to overheating of them...thats explain why the voltage drop