Voltmeter went to 18v turned truck off now truck dead

[Griffon]

I noticed my battery indicater light on, looked at voltmeter it said 18v so pulled over and turned truck off. looked under hood seen some batt acid on batt then checked everything. all looked ok except battery leak so tride to restart to get home. truck dead as if no batteries hooked up?
Can anyone tell me if this is alternator! and will that cause no power or do i need to find a main fuse some were????
All help apriciated

[Griffon]

Forgot stats- 96 ford 7.3 diesel

[letitsno]

Sounds like alternator.

[Griffon]

Thanks for quick reply.
If alternator goes does that kill all power to the truck? I would think that would be caused by a fuse or relay of some kind. Any guesses what and were to look?

[ZMANN]

batt acid on top is an overcharge ( apparent) ,,
test them to see if they still have voltage or were cooked ?

[Griffon]

Cked batteries bit ago! so dead maybe 2v tied together checked with load tester, but didnt bother doing load test, checked water one full other one down 1/4" PUT CHARGER ON 10AMP CHARGING NOW! So did alternator go bad and discharge batteries? That is the question????
just turned key on and dash lit up so that works at least but didnt even try to start! need to figure out why killed batteries! When this happened it was day time and i shut it off whithin a block of noticing it

[ZMANN]

I think you alt went to full charge and boiled your batts

are batts toast ??? refill with distilled and see if they take a charge and hold a charge .

Why did the alt go to 18v ?? loose connection bad alt?? .. I would pull it and test the alt first if you don't find a obvious problem when checking the connections ?

[porkchop6209]

Go read my post under A Word of Caution, scroll down a few lines under engine 911, you'll see it. Be careful and thoroughly test the fully charged batteries and alternator seperate from the truck. You don't want to go toasting computerized components, they aren't very tasty, even with butter and jam.

[ianstew]

i would recomend having your alternator tested. regulator went bad most likely.......