Alternator issues

I'm having some trouble here fellas. I've replaced the alternator, gone through numerous batteries, replaced the battery terminals, and double checked belt tension. How crazy is the wiring between the alternator and the battery?? I put a brand new battery on it a while ago and volt tested it. It was pulling 12.6, which apparently is what it should be pulling. Once I start the truck and test it, it ticks down like a clock..12.60, 12.59, 12.58, etc. Any help??

$120 high output GM one wire!!
or
$400 LCE high output D.R.

i have the same fucking problem! i can't run my AZ and headlights at the same time

is this problem at idle or while under load or higher rpms? toyotas (at least mine) didnt charge for crap at idle but while around 3,000 rpm did great. if i had my tv stereo and compressors running my stereo would start to turn off and on. and if i revved it up then it would stay steady, make sure also no oil is on your alt. i had a leak somewhere it got on mine and fried it..

The problem is the same at idle and with increased RPM's. When I bought the truck, dude told me it had a shot alternator. What I should have done was get the original one bench tested before getting a new one, but what can I say, I'm an idiot!! Anyway, brand new alternator. I'm thinking it must be something with the wiring. So where would I get those wire(s) and is there any way to test the original ones?? Also, are they a total pain in the arse to hook up??

I swapped to a GM one wire, and ran it straight to the starter and it works just fine.

Would this eliminate the issue if it is the wiring?? Also, the GM's fit our yota's?? Lastly, where's the best place (and best price) to get one of these bad boys??

If the wiring is bad it would eliminate the issue, because it bypasses the stock wiring. It won't hook up to your stock gauge. I can't if the stock gauge is an ampmeter or a voltmeter. But whichever it is, you need the other one. Lol. I haven't seen mine in a year so I can't remember.

It will fit if you modify the brackets. Its pretty simple. Took me 30 minutes.

I got mine on eBay. 100 amps, $90 shipped.

Thanks for all the input guys. I'll dive in and see what's up. I'll be back if I have more questions!!

A word of caution for what its worth, the GM 1 wire alternators work fine, easy to hook up, easy to mount, but they have no load sensing with the 1 wire configuration, they just put out a consistent set voltage, as the load increases with headlights, stereo's amps, compressors, heater, wipers ect.ect. the alternator can't sense the load increase and puts out the same set voltage, with enough bells and whistles running the draw can exceed the output.

Good to know. Right now I've got the alternator pulled and I'm gonna get it tested and go from there. If the alternator is good, then everything has been changed minus the wiring. I hope it's not the wiring, because I suck at electrical crap and it looks pretty crazy.