Please Help with Electrical System/Charging Problem :(

[Purple_Haze]

Hey Guys,
First of all, great forum, great mods, lots of helpful ideas. Cheers!

I bought my first chevy about a month ago. It is a 1500 Silverado with 4.8 engine and auto tranny. Did about 3k on it within that time, not work related. Everything was fine back then. About two weeks ago i got a new alternator installed because the old one was only putting out about 12volts. The new/rebuild one, was putting out 14+ all the time. Last week i noticed that it was doing only about 12 when truck started, and my "battery thing" came on. i revved the truck it went away, and worked fine for 2 more hours. It happened to me for few more days, only when truck started. Not while driving. Went to mechanic, told him the problem he sent it out, got another one.
This one worked fine, except when driving at night, the lights and dash would go brighter and darker by itself. You could see movement on the gauge, but it was minimal. Took it to the mechanic, and told him to stop giving me this rebuild crap. Guy got me a new one. Brand spanking NEW. We put it in, everything was fine. Today it started doing same stuff.... when started it does not charge, and sometimes while stopped at the lights its below 14 as well and the light comes up. Please help, as i am lost and dont know what to do. The only thing that i did to the truck was, the 4 headlight mod. i disconnected it today, and started it couple of times, while playing with the wiring harnes at the electrical centre, and no difference. Please Help.

[BlenderWizard]

Sounds like, for some reason, you are getting power "dips" and "surges." A capacitor would cure this problem, probably, but you shouldn't have to install one to make your truck work right

[sc_customs]

I was having voltage drops recently (truck was struggling to start, battery wouldn't stay charged about 10v). I checked the battery cables and found they were loose. I know it's kind of an obvious fix but easily overlooked.

[Purple_Haze]

I checked the plug on the alternator, wire going from alternator to the "BOOST" box, and cables going to the battery. It is a DELCO Professional Series battery. I need that fixed because i quit my job few days ago, and wanted to go on my own, but can't have something like that happening to me especially right now .

[77newguy]

did you check your voltage regulator...autozone should be able to test it for you!

[Purple_Haze]

Voltage Regulator? I thought that these things were external in vehicles pre 85?????? Doesnt alternator have one built in???

[HanibalTheCannibal]

Originally Posted by Purple_Haze

Voltage Regulator? I thought that these things were external in vehicles pre 85?????? Doesnt alternator have one built in???

Yes they are internal. If you are getting rebuilt alternators, sometimes you have to go through a few to get a good one. "sometimes". But you may have a current draw on your vehicle somewhere that is intermittent. Very well could be a bad connection. Make sure the ground is good.

[Purple_Haze]

The problem is, two that i got were rebuild, the third one, is not, ... its a brand new Delphi automotive alternator. And like the other ones were painted, taken apart, etc... this one has been not.