Voltage fluctuates, new Alternator & Battery

[Capote]

So still having issues with the voltage fluctuating anywhere from as high as 14.3 down to as low as 12.1. Consistently does this on and off religiously everyday when sitting at a light or just in park. Voltage rises during acceleration, but decreases once I take my foot off the accelerator. Figured a new alternator would fix this. After I installed the new alternator and let it idle 20min after reconnecting the battery it held strong at 14.0 volts, but once I drove her right around the corner to the gas station I once again was seeing the ride and fall I always see with my voltage. It's visible on my dash gauge too, needle sways back and forth with the voltage reading on my voltage gauge installed in my dash bezel. No idea at this point what to do next besides but the correct battery.
Any Thoughts?

Video so you can see what I am talking about:
https://www.youtube.com/watch?v=mlHyob8v5M4&feature=youtube_gdata_player

 

[BlazingTrails]

I found this little excerpt on TV you might could check........

"OK, as of today 5pm EST. It has worked fine since I separated the power & ground wires leaving the battery on there way to the fuse box. There was a slight melting in the ground wire insulation. It really doesn't make sense to me why this seems to have fixed the problem. I can say this though I drove over 200 miles the last few days and it hasn't done it (at least I haven't noticed & I have been watching my gauges more than the road.) So, I figure I am gonna re-route those wires and hopefully the problem will be solved. As of now there is just a large piece of electrical tape in between the two wires."

If it is not that it is probably your battery. The Electronic Load detection system is calibrated for a certain amount of amps in the battery and it is probably throwing it off.

 

[MAY03LT]

What battery is in it now?

Do you gots any charging system codes?

 

[Capote]

What battery is in it now?

Do you gots any charging system codes?

This is what I have hooked up now bud, obviously not for our TB's, but it was meant to be used temporary until I could get a proper one

EDIT: I just had a code pop up while making this post, I'll have to wait until after work to get on my tablet to read it on Dash Command

 

[MAY03LT]

p0562
p0563
p0621
p0622
p1637
p1638

Hopefully one of these pops up.

 

[Mounce]

May, are our alternators internally or externally regulated?

 

[MAY03LT]

I know the early ones (4 pin/2 wire ad244) is internal not sure about the fancy ones with the gbcm.

 

[Mounce]

Oh okay, so 'potes is internally regulated?

Welp, my idea is out the window lol.

 

[Capote]

Welp.....code wasn't any of those. Was for EVAP leak again.....I'll deal with that after my deployment

 

[MAY03LT]

Does your scan thing read engine data? If it does see if the ignition 1 voltage matches what's on the dash. If the scan thingy can't read it it's no biggie. I'll post the troubleshooting steps in the morning.

 

[Capote]

I'll have to double check once my little ones are off to bed. I know it does show an in depth list of live data when runnibg, just have to remember where on that app.

 

[BlazingTrails]

Welp.....code wasn't any of those. Was for EVAP leak again.....I'll deal with that after my deployment

My evap code came back on today too. Gonna smoke it out very soon. P0442 fml

 

[MAY03LT]

Sorry for the delay things have been crazy around here. I read another post about a starter problem so I wonder if the engine block to chassis ground is suspect or B+ alt/starter leads is suspect.

 

[Capote]

capot1.JPG

capot2.JPG

capot3.JPG

Sorry for the delay things have been crazy around here. I read another post about a starter problem so I wonder if the engine block to chassis ground is suspect or B+ alt/starter leads is suspect.

No problem man, thanks for the info. I unfortunately don't have a scantool to even begin this troubleshoot.
My starter has been misbehaving though, sometimes it works like a charm, other times it barely gets going

 

[IllogicTC]

I wonder if that's a symptom of the starter or of the battery? Perhaps the battery has an internal fault.

Fluctuating voltages, you said you have a new battery and alternator... the only other things I could think of is

-Bad belt. This one is obvious, but you would really expect decreases to happen with acceleration as it would cause slip

-Bad tensioner. I can't prove this one, it's just a theory, but if the spring were inconsistent in the tensioner it could cause certain issues. I've had plenty of experience with (conveyor) belts, and have studied plenty in the slow time on the tensioners of those units, at least. One thing to note is that during an acceleration event, the belt actually stretches a little, one of the jobs of a tensioner is to take up the slack in this scenario. Perhaps it is properly doing so, or perhaps if it isn't the rest of the system is, then when at cruise/idle where the tensioner is trusted to keep everything tight it's not doing quite as good of a job. I wish we had some reference material on how much pressure the tensioner is expected to give, as then it could be measured and compared.

-Bad battery, as stated above, or perhaps a questionable connection.

 

[Capote]

Thanks for the input man. Starter really has been an annoyance lately, it always works, but is inconsistent. I plan on replacing it for sure.
I was inspecting my belt during my alternator install and it looked good still no cracks or anything to suggest a lot of wear. Tensioner really could be a possibility it seems then. I was going to stop by AutoZone or Advanced Auto to get a new idler pully & proper battery, might as well look into a new tensioner and belt too. Process of elimination

 

[Mounce]

I'd start off with the battery because you know either way you're going to replace it. If that don't fix things, then move on down the line of diagnosing the issues.

 

[Capote]

I know buddy
Hoping that'll do the trick, who knows [emoji53]