Charging issues

[dna9656]

My 06 1500 Z 71 flex motor VIN 3GNEK12ZX6G101883 I have an intermittent red battery light on the dash. Thursday the light came on and went off, I didn't see it till Friday, was on for 26 miles. Sunday the light comes on, got it checked at Autozone the batter was so low it wouldn't register, guy couldn't check the system with a low battery. I charged the battery all night, went to AZ with no red light and it checked fine, got it checked again at another parts house and it checked good. left there to drive home and the light comes on. I turned around went back to AZ, the system checks good while the red battery dash light is on.
So the battery went flat (low), the battery is a 18 months old.
I cleaned all the connectors, applied dielectric grease to the connectors before I charged the battery.
There must be a charging problem or the battery wouldn't go flat yet the system checks good.
Anybody got any ideas?

 

[redheadedrod]

You could have a bad Diode in your Alternator. Some systems won't see a single bad Diode because they just look at the voltage. You could have a bad battery as well. It is hard to know for sure. Could just be bad wiring...

I would suggest looking at doing the big three upgrade regardless of whatelse you find.

You can pull the alternator and bring it to a shop and they should be able to test it for proper output. Most of the systems that test while in the vehicle really don't work as well. As to your battery... If your alternator has 1 diode burnt out it can still be putting out 14.5 volts but you would likely hear a very noisy radio or other issues because it would be a total square sine wave output. And your computer would still show a charging issue light.

Things like this is why I own two vehicles so I can fix one when necissary...

 

[dna9656]

Thanks for your response!
Around here (S Kitsap County, WA. State (not for from the narrows bridge) AM radio STINKS lotsa noise and FM isn't much better.
The battery is 18 months old and has not exhibited any bad behavior until now, i thought it might be a bad cell, (they show up when it gets cold) but it's been tested several times now and charged up without a problem.
So far as i know overhaul kits for alternators aren't sold anymore, they went the way of bearings and seals for water pumps (the re-builders make too much money off of us) I wouldn't know where to look for a diode trio for this alternator, or any other one either. Back in the day you could get stuff like that and solenoids too.
I sure hate buying an alternator when all I need is a rectifier or diode trio but the thing has 190K miles on it too so the bearings are prolly going south soon as well.
Yeah, I have 2 vehicles as well.
Best price in the country for this alt. is on Amazon.
My truck came with a 145 amp alternator, any reason I shouldn't get the 160 amp? Bosch sells a 150 amp they show for my application.
Does anyone one know the alternator type, what Bosch calls it? Bosch doesn't even ID the thing beyond amp output. NEW INFO Bosch model Number:0986UR0560
The site below shows pictures of the "Generator Battery Control Module" it's located on your negative battery cable. I believe this could be my issue; I think this inductive sensor controls the little red battery symbol (Shows the battery current direction) on the dash. Anyone know how to trouble shoot it?
https://www.amazon.com/Genuine-GM-Module-Part-15263889/dp/B00TAB2DS2/ref=sr_1_1?keywords=15263889&qid=1573501745&sr=8-1

 

[redheadedrod]

You can always get one of these for about the same price. I am running one on my truck now...

https://www.amazon.com/gp/product/B017KVWOSC/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

 

[dna9656]

If the Generator Battery Control Module isn't working correctly is wouldn't matter if the truck was connected to the Grand Coulee hydo electric dam; (it makes 6,809 watts, the highest output of any dam in the in the US) if the module doesn't allow the alternator to produce it ain't gonna charge.
See bottom of this post for description of how the Generator Battery Control Module works.

(https://www.silveradosierra.com/electrical/alternator-not-charging-with-aftermarket-stereo-t57169.html#p604873)