over charge on 24v 12v alt

[Jody Jack]

my alt's are over charging the 24v is pushing out 30v's and the 12 is pushing 18v its fying fuses of course and htere is no voltage reg on it any ideas how to fix this or do i have to buy a voltage reg for each alt?

[Rytari]

no voltage reg? you sure... without it your alt wont work at all... id say you got internal regulators there... and if you have 2 alts, both making overvoltage... you got wiring problem... bad contact, bad negative contact...

you get +30 and +18 from alt or from battery? if it is only from alt +, you have bad wire between alt and batt. if it is in batt either voltage regukltor wont "see" voltage of your system or your alt(engine) not groundet properly...

just my opinion... better ask some electrical...

for 12v alt max should be 14.9v and for 24 its 29.8v over this will wear battery rapidly...

for normal use 13.8-14.4v (27.6-28.8v) should be fine

[Jody Jack]

i checked each alt at the ground and pos studs while it was runing and it gave me thou readings. it very well could be bad wireing some where this is a cucv and the nato spec wireing is all butchered by its old owner. so i been peaceing it together very slowly. the volt regulater must be in the alts cause i looked all over for it and the wire diagram i have says its sapoused to be in this one location and its not.....

[Rytari]

delco style alts have internal reg...

i think you have those... there is B+ wire on rear... and 2 wire connector on side... this 2 wires are for the reg... both of them needs 12v when running,

http://www.oldengine.org/unfaq/10si.htm


like if you have really 14v but wire is 1.5 short, alt will send out 15,5... i had this also once..

[ccatlett1984]

the alternators on the CUCV's are delco 27si with isolated grounds.

I would pull the alternators and have them tested, go to a alternator shop and specify that alt's have a isolated ground. autozone/orielys cant test them properly.

If the alternators test good start looking for a burned up fusible link on the drivers side firewall, although that should only cause the drivers side (gen1) to read high.

[DieselCrawler]

I have a former CUCV, and converted it to 12v. Change the starter, find one good alt, and swap a few wires, you're set. The isolated ground throughs things off when you take the alt to be tested at a shop... I got one, from a '70's caddie I think, same case, just not iso grd, bolted right in when my iso grd one went bad.

Before I changed to 12v, I had a solinode between the batteries, to isolate one, as it was still needed, but only to start the truck... was able to keep one alt just for the 2nd battery, and the other alt and battery for the regular stuff the truck has...

I ended up with a burned fuse panel a few years later, lost headlights, changed EVERY THING... cab wiring harnes, motor wiring harnes, starter, all 12v civvie stuff now...

And in the noise department, as of Saturday night, and at the direction of Captain Morgan, the ol' truck now has 3 1/2" straight pipe (3" EMT electrical conduit) from the turbo, with a turn out just infront of the right rear wheel... funny the stuff that happens late at night when hangin' out with friend around trucks and welders and such.... we've lost a lot of mufflers that way... have a hazy memory of something like that happening to the F350 too.....