Re: Speaking of trucks and

I have a 2007 GMC Canyon Crew Cab, which I affectionately call my Trash Hauler. It was bought on the cheap about three years ago, $4000, put another $1800 into it replacing all wear items, and defective GMC junk like plastic tailgate and seat adjustment handles, etc. It became an ultra-reliable 2nd or 3rd vehicle.

Suddenly last week, the charge idiot light started coming on, with a message "Service Charging System" in the message window on the instrument cluster. Being a veteran DIY mechanic, I pull out my Volt-Ohm meter, and find out the alternator is charging TOO much, over 15.5 volts.

Since I know everything in the world has been discussed somewhere on the interwebs, I research this here issue. Come to find out, this, and all GM vehicles of this era have a variable charging system, which is based not only on battery CHARGE, but battery TEMPERATURE. Now you know why some of your batteries are encased in plastic boxes, and actually have air inlet hoses going to those boxes.

GM used a module to vary the ground that the alternator sees, to simplify the explanation. These modules, which actually have to work with a REAL ground somewhere, can fail, and in northern climates where the roads are salted, etc, the ground wires can and DO fail. Check out the best mechanic on the internet, Eric O at South Main Auto Channel (YouTube) in upstate New York, if you don't believe that.

Anyhoo, simple fix for this issue is to run a direct ground from the motor to the negative battery cable, which in effect takes that module out of the circuit, and lets the alternator charge vary like it used to before all that foolishness was introduced. Now, this maybe could cause some issue with a cold battery in northern Siberia, but in South Carolina, somehow I think I will be ok. I drilled a hole directly into the steel alternator bracket, ran a ground cable from that point to the negative battery cable, and VOILA, system suddenly charging 14 volts, as normal with headlights on.

And, idiot charge light is off, message is gone. I like it. Sometimes the interwebs CAN be useful for something other than bewbs.

Father G®

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How about a more 'southern' flair?

Nov 20, 2024, 2:01 PM

I got me a 2007 GMC Canyon Crew Cab I like to call my Trash Hauler. Bought her cheap ‘bout three years back for $4,000. Then I threw another $1,800 into her fixin’ up all the wear-and-tear stuff, plus replacin’ that cheap GMC junk like plastic tailgate handles and seat adjusters. After that, she turned into one heck of a reliable second (or third) ride.

Well, wouldn’t ya know it, last week that dang ol’ charge idiot light comes on, flashin’ “Service Charging System” in the dash window. Now, I ain’t no stranger to wrenchin’ on my own rigs, so I grabbed my trusty Volt-Ohm meter and started diggin’. Turns out, that alternator’s workin’ too hard—pushin’ over 15.5 volts.

I reckon if there’s a problem in the world, somebody’s done talked about it on the interwebs. So I do some diggin’ and wouldn’t ya know, this here issue’s a common one with GM vehicles from that era. They got this variable charging system that don’t just watch the battery’s charge, but also the battery’s temperature. Makes sense now why some of y’all’s batteries are sittin’ in plastic boxes with air hoses runnin’ to ’em.

Here’s the deal: GM stuck in some kinda module to vary the ground the alternator sees—simplifyin’ things, supposedly. But them modules are finicky, and if you’re in a place where salt eats up your roads (and wires), that ground can go bad faster than a hot biscuit left out too long. Don’t believe me? Go watch Eric O at South Main Auto on YouTube up in upstate New York. That man knows his stuff.

Now, the easy fix? Just bypass that nonsense. Run yourself a direct ground cable from the motor to the negative battery terminal. That takes that persnickety module right outta the equation, lettin’ the alternator do its job the good ol’ fashioned way. Might not work in some frozen tundra like Siberia, but down here in South Carolina? We’re good as grits.

So that’s just what I did. Drilled me a hole in the steel alternator bracket, bolted a ground cable from there to the battery’s negative terminal, and bam! System’s sittin’ pretty at 14 volts, even with the headlights on. Charge light? Gone. Error message? History.

Sometimes, y’know, the internet ain’t just for giggles and bewbs. It actually helped me out on this one, and I gotta say, I like it!

How’s that for some southern flair? 😊

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Overcoming GM Engineering.

Sir, this is a Wendys***

So, you are saying your fellow Lungers can't follow this story?

Speaking of trucks and

I told ChatGPT to make fun of OP. Results Entertaining

So, you get off on being Holier than Thou? Got it.

BTW, that total $5800 investment you made fun of, was still about 2 grand below

Bro, I am glad you have decided to become a Lunger, full stop

Have not seen my ex since July 1, 1985 in court.

I'm not sure Tigermanac is aware of these rules.

How about a more 'southern' flair?

That was much easier to read. Thanks AI overlords!***

The vent from a battery enclosure has nothing to do with temperature

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