Charging System

[ronbz]

The only alternators that I know that will charge 14.5 volts are AC Delco new or remann alternators. Why aren't aftermarket manufactures of alternators govern to do this? Every alt. that I have purchased so far from the aftrmarket only charges 13.5 at the max. Example, my cousins 2005 S10 Blazer had an alt. dropping below 14 volts and I put a remann AC Delco alt. on it and it kept the voltage at 14 or above. In the past I got alt's from the zone and the best they did was 13.5 on a good day. I have a 83 1 ton 454 Crew Cab and I put a Diesel in it from my Suburban which rusted out and had 2 or 3 different alt's on it and never showed 14.5 volts even with a good digital volt meter and good batteries. I blew up the Diesel after putting a trubo on it and went back to the 454 with 2 batteries. I now have a 91 105 amp alt. on it and the most I can get out of it is 13.85 but I have 2 cooling fans on it and a electic fuel pump and it wont even keep up to 12.65. Even more rpms dont bring the voltage up. Vans electric says they have a 140 amp alt. that they use on trucks that have plows to keep up with the raising and lowering of the blade motor. I have worked at a dealer for 20 years and if the alt dont keep up replace it. Recently I ran into that voltage saver mode with that amp system attached to the positive cable and after a while the volt meter ran down to 12 volts so I replaced the alt. The new one started doing it again. The battery checked good but I replaced it and the volt gauge stayed at 14. I hate being wrong but I think that amp system fooled me. Ive tried 3 different 105 alts. around the 90's on my truck and sometimes they whale, not whine but whale. Most of the time I have 12.25 to 13.85 volts. I've ran wires straight from the alt to the batt and the same output. The brown wire comes from the gauge an acts as a turn on switch for the 91 alt. The alldata desciption says the other wire is not needed but I hooked it up straight to the positive lead on the back of the alt and it helped a little but after a trip to the dragstrip the other night it started charching less again. I'm thinking about taking the old 68 amp alternator and putting an AC Delco Voltage Regulator in it and see if it charges 14.5 volts and see if it can hold up with all fans runnig but I doubt it. Anybody ever had a problem with this?

[jrod332]

I have a 145 amp alternator and dont have any issues.