"Battery Not Charging"

This was the greeting from my DIC this morning and the IC voltmeter confirms it.
Zero fault codes according to Torque Pro.
So I put the truck where it needed to be to unload it and will proceed with fixing the issue.
241,000 miles on the truck. What's the most likely thing? Ran great yesterday. Alternator? That's of course my first thought and will have it tested. Anything else I should look for?

The GM alternator that's in it right now is the original as far as I know. A quarter million miles isn't bad, but is there an OEM that's a better unit for a comparable price?

www.alternatorparts.com

I've been trading with them (him) for a couple decades. Top notch products with no issues, ever. I upgraded mine to a higher output, more robust single generator when I was considering the OEM solution of duals. Still going strong with more power output at idle than the OEM at full speed. About a dozen other alternators and starters for other vehicles. The 2005 M/Y could be either 2 or 4 pin connector, so make sure you get the right one, either way. Give him a call. It's been a couple years since I've called, but he use to answer his phone.

Thanks Dmax! Didn't know that about the 2 vs 4 pin connector, so I'll pay attention when I pick up whatever I pick up to replace this one. Rumor has it that the 145 amp will fit in the same spot the present (105, I believe) one is in, so I might go that route. Making lunch now and will head to the driveway after to pull out the dead unit.

Replaced the alternator (105 amp because the 145 amp unit was considerably bigger) with a new not rebuilt unit. Since both idler pulleys and the tensioner assembly pulley were getting noisy, and since the serpentine belt had well over 100K miles on it, those parts were replaced as well. Permatex antiseize paste on all the bolts, silicone spray on all electrical connections, torqued to spec.

An easy job, even in a snowstorm...

My twin alternators are still going strong after 10 years and 181,000. This is a far cry from years ago when I had to replace GM alternators every 2-3 years in several different vehicles.

Quote:

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Originally Posted by rapidoxidationman

Replaced the alternator (105 amp because the 145 amp unit was considerably bigger) with a new not rebuilt unit. Since both idler pulleys and the tensioner assembly pulley were getting noisy, and since the serpentine belt had well over 100K miles on it, those parts were replaced as well. Permatex antiseize paste on all the bolts, silicone spray on all electrical connections, torqued to spec.

An easy job, even in a snowstorm...

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Sounds like you did a great job.

It seems that more and more incandescent lamps are being duplicated in LED nowadays. LED lamps only draw a fraction of the power required to light a traditional incandescent. Trucks towing during a summer evening - with A/C running, every light on, plus stop/turn lamps, and it becomes a struggle for the alternator to keep up. LED might be a good way to go for pickup truck owners who find themselves in that situation. Should help the alternator last longer too - though I'd guess you got your money's worth from your truck's original... :)