New Alt, Low Voltage issues

[wew lad 5,000+ posts]

Thoroghly clean your throttle body, if that doesn't work, have the PCM reprogrammed to increase idle speed.

This^ Clean your throttle body and MAF sensor.

Some of those posting are pretty intelligent, but they're full of **** when they say 500 rpm is too low. I bass hard and my dual alt's regularly see 400-600rpm at idle after dropping from 650rpm. Obviously I lose output, but nothing like OP is seeing. Yes, they're stock pulley's

I have the exact same engine as you, and two alternators so much more load. One DC Power 270xp and one stock ad244. If you need another alternator to test go get one from a junkyard for less than $50.

Your alternator has a problem. When you pull it off and swap the other in, pull the plastic cover off the back. Look at the brush holders, pull them off if you have to. I bet they're either melted or making poor contact. Other than that the voltage regulator or diodes are fucked. Don't ask me why, I don't know. This isn't the first time I've heard of someone getting a mechman alt (this is on a silverado forum) and having issues. Mechman argued with him for 5 MONTHS before they let him send it back and what do you know? They found a problem with the alternator. Go to an alternator shop if you have to, mom and pop alt shops are the ****

VERIFY FIRST that the alternator is bad, then send it into mechman detailing what you've done to troubleshoot it, and the issues you're having. Be sure to verify voltages on the wiring into the alt. If it's two wire (1 is the positive post, 1 is in the plug) the wire in the plug needs to be between 10-13v. If it's below that the alternator won't excite, if the alternator won't excite you won't get any output and you'll see the 10v you're talking about.

Based on your location in topeka there's two places:

http://gossersautoelectric.weebly.com/

http://www.electrolifebattery.com/

The second only looks like a battery sales center

 

[CplCuddles]

Your alternator has a problem.

Thoroghly clean your throttle body, if that doesn't work, have the PCM reprogrammed to increase idle speed.

I had a similar issue with my mechman 270

 
 
Ok so update guys, I haven't figured out what has been the issue so far. I haven't been able to clean my throttle body and MAF Sensor, but I don't honestly see how that would make my battery die overnight tbh. I just got a new job finally so I should have income coming in to start actually fixing issues, but I still have to figure out what the f'ing issue is. Today I came out to my Tahoe after the night and it was sitting at 9.9V, I had to get it jumped for it to start. As soon as it started straight up into the 13Vs and when I started driving stable at 14.6V. I tested Voltage while the vehicle wasn't on and it said 10.1 with my Fluke DMM(My in-car VM was set with a cheepo dmm), at the battery and Alt. I did a parasitic draw test by disconnecting my neg batt terminal and using my dmm in amp mode and connect the - batt terminal and the negative hookup. Upon doing this it jumps to 1.7Amps for about 2 seconds, drops to .7Amps, then down to .16Amps and finally rests at .06Amps. I figure that is due to the computer etc etc. So if I have no current draw... how tf is my battery dying? Pics follow...
 
 

 

[CplCuddles]

Wouldn't let me edit my previous post

(Pic1) 10A Unfused, on Amps DC. + probe on my neg wiring, - probe at batt -

(Pic2) Initial jump up into the 1.7 amp range

(Pic3) After about 2-3 seconds drops to .7ish amps

(Pic4) After about 5-10 more seconds, drops to .17ish amps

Then finally after another 30ish seconds drops to .05-.06 amps. (don't have pic of that)

 

[wew lad 5,000+ posts]

Your battery is a POS and the internal resistance is so high it drains on its own

 

[CplCuddles]

Your battery is a POS and the internal resistance is so high it drains on its own

I got the battery load tested (dunno if it tests the int resist) and they said its perfectly fine.... is that a thing? .-. how would I even test that..

 

[wew lad 5,000+ posts]

I got the battery load tested (dunno if it tests the int resist) and they said its perfectly fine.... is that a thing? .-. how would I even test that..

Load tests can be notoriously hit or miss. How old is the battery? Optima's **** to begin with, I'd just go buy a duracall AGM and swap that in if the battery is more than a few years old 

 

[wew lad 5,000+ posts]

Those electronic load tests that is, an analog load tester does a pretty good job

 

[CplCuddles]

Load tests can be notoriously hit or miss. How old is the battery? Optima's **** to begin with, I'd just go buy a duracall AGM and swap that in if the battery is more than a few years old 

Not even a year old. I was actually thinking about getting a Northstar AGM, I've heard those are perty gud.

Those electronic load tests that is, an analog load tester does a pretty good job

I got it tested at O'Riellys, dunno what kinda test they use, prob electronic.

 

[wew lad 5,000+ posts]

Not even a year old. I was actually thinking about getting a Northstar AGM, I've heard those are perty gud.

I got it tested at O'Riellys, dunno what kinda test they use, prob electronic.

If it's not even a year old get it warrantied lol then sell it if you want 

You need to do some actual testing to determine the problem. Right now we're just speculating over and over. I gave you a few ways to rule out the alt or battery

 

[CplCuddles]

If it's not even a year old get it warrantied lol then sell it if you want 

You need to do some actual testing to determine the problem. Right now we're just speculating over and over. I gave you a few ways to rule out the alt or battery

Ok so, I did swap out my alt. Still had issues, its been so bad its been dead everyday this week. Figured it had to be the battery,  nothing else made sense. Drove to autozone and had them test it. Bad battery.. went to O'Reilly tied to tell me it can't be the battery while testing then when I told him I got it tested and they said it was bad then he agrees with me. I told him I wanted to warranty it due to it not even being a year old. He then sees my power wire and when we get inside tries to blame my "stereo." He said that they won't warranty any further issues, but I traded up for a yellowtop so hopefully I shouldn't. I don't see how it's possible that my 1500W system killed that battery. I had the same system in a car before it for longer, lower amp alt, and a non-agm battery. 

Tl;dr battery was the issue

 

[wew lad 5,000+ posts]

Ok so, I did swap out my alt. Still had issues, its been so bad its been dead everyday this week. Figured it had to be the battery,  nothing else made sense. Drove to autozone and had them test it. Bad battery.. went to O'Reilly tied to tell me it can't be the battery while testing then when I told him I got it tested and they said it was bad then he agrees with me. I told him I wanted to warranty it due to it not even being a year old. He then sees my power wire and when we get inside tries to blame my "stereo." He said that they won't warranty any further issues, but I traded up for a yellowtop so hopefully I shouldn't. I don't see how it's possible that my 1500W system killed that battery. I had the same system in a car before it for longer, lower amp alt, and a non-agm battery. 

Tl;dr battery was the issue

it won't kill the battery unless you run it way too low and deep cycle it A LOT or put huge load on it. like i said, optima batteries ****. you probably got a bad one