"More power!" (electrical / charging)

[Reprise]

So, the last couple of times I've started the Sierra up, I noticed a low in volume (but high-pitched) squealing, coming from high up in the bay.
I've also started noticing that my voltage gauge has started reading lower than normal (in the past, it would register just about the midpoint ('14' volts) when it was first started and charging the battery back to 'normal'.) Now, it's showing two notches below that, and occasionally dipping to the large notch between the 'too low' 9 and 'just right' 14) The 'quarter notch', if you were reading it like a gas gauge. Apologies for the inexact description; just relaying what I'm seeing, without quantifying it with a multimeter.

Anyway, taking those two things into account, I figure the alternator is on its last legs. Might have been hastened by me converting to the e-fans; not sure. I can definitely see the voltage drop when they come on in series, even before it started reading 'low', as it does now.

Since we've been discussing our current favorite toy, the bluetooth-based battery monitor that littleblazer, blckshdw and myself all use from Amazon, I figured I'd run a 'charging test' from the app, and share that with you, just as an 'FYI'...

(background -- to run this test, the app instructs you to start the vehicle, turn off all electrical loads (such as radio, HVAC), and turn the headlamps 'on'... then run the engine at 2500rpm for a minimum of 5 seconds)

So, what we see here, relatively speaking, is an alternator that's marginal. Just enough to keep the battery from draining, but not charging it at the normal rate (which would be > 13v at idle, and as high as 14v under rpm load (not constantly, but cycling between 12-14)

My alternator, since the truck is an 'HD', is a 145 amp -- the 'DR44' / DR44G. I'm pretty sure it's a reman, too. Didn't put a new one in when I did my cam / head swap, because: a): it was working just fine, b): it's literally at the top of the engine bay and takes 5-10 min to R&R, and c): I have a spare alternator from the Envoy for emergencies (not the same amperage, but it's a 4-pin, just like the one in the Sierra.

But now... since it looks like this alternator is about to bite the dust, I have some options to consider...
First... there are rebuild kits available for this thing. Less than $50, shipped. Not a ton of skill needed (although if the issue is with the diodes, it's a lot of trouble, because they're soldered on, etc.) However, because of how the alternator is disassembled to replace the front / rear bearings, it's apparently better to rebuild a 'new' alternator, and not 'rebuild a previously rebuilt one'.

That's fine... new ones aren't *that* expensive, relatively speaking.
But... if I'm going to need to fix the charging system, I may as well consider upgrading what I've got.

The full-size pickups have provision for two 12v batteries (trucks with the 6.6L Duramax require two batteries, because of the extra power needed to start that beast). I'd need a battery tray, a couple of cables & relays, and a couple hours to give myself a nice upgrade, from a standpoint of amp-hours. And for my future mod plans, camping, etc. -- it just makes sense.

In addition to the dual battery setup, I'm also thinking about boosting the alternator. I've got a couple of different options there, as well.
- Higher output alternator (I can get a 220A from RockAuto, for about $175 or so)
- Dual output alternator (with two charging lugs -- I think the DMax uses these - ? Not sure)
- Dual alternators (I don't like this option, but it's an option)

And, of course, on my local CL, there's a guy that's been trying to sell a chromed 240A alternator for probably a year now. Yes, I said 'chromed'... (cue Ric Flair 'woooooooo' sound) He's a bit of an @sshole; I'll spare the story for now.
But... since it looks like I need an alternator now... ?

 

[NJTB]

Before you go through all that, are the battery cables good? If you can, load test the negative cable.

 

[TollKeeper]

You have the option to test with your spare alternator, so thats where I would start.

Other than that, I would do the dual battery, unless you are planning for a big radio.

Dont bother with the relays, we wired in our 6.0 shop truck for dual batteries (to jump start semi trucks) by just running a 2/4 guage cable across the radiator shroud, and to the battery.

 

[Mooseman]

Unless you know that your stator and rotor are good or know how to test them, I wouldn't go the rebuild your own route. I had rebuilt my own years ago, like on my 78 Camaro, but haven't gone that route since.

Unless you really need dual batteries for extra load, it shouldn't need it. Just extra weight and stuff to fail.

Extra amps? Might be needed now with the e-fans. What's the normal amps on the trucks that came with the fans? Might also be needed for charging the RV trailer's batteries if you boondock. That could pull up to 30 amps according to that fuse.

Which alternator to get? I never had much luck with rebuilts, even ACDelco. Had much better luck with new Chinese ones except from one supplier which doesn't sell them anymore (Prime Choice/AutoShack) and also had bad luck with Remy.

 

[Reprise]

Before you go through all that, are the battery cables good? If you can, load test the negative cable.

Gee, you're a buzzkill... Seriously, tho... before I buy / do anything, I'm going to quantify with actual measurements. Appreciate the tip

You have the option to test with your spare alternator, so thats where I would start.

Other than that, I would do the dual battery, unless you are planning for a big radio.

Well, I have been thinking about a 'portable' amp install (not a mini-amp, but using something like Anderson connectors so that I can swap the amp between vehicles.) The amp is about 1500 watts, but that's split across five channels, and I'm not planning on 'bumping while towing', to be honest -- if I hear trouble from the driveline, I want to hear it.

There's another thing I want to hook up for 'occasional' (emergency) use, and it's a known battery drainer. Sorry to be a wise-ass and not say what it is; I don't like to 'promise' something and then wait months / years to deliver on it. LOL You'll probably guess it from another post I'm making today.

Unless you really need dual batteries for extra load, it shouldn't need it. Just extra weight and stuff to fail.

See above...

Which alternator to get? I never had much luck with rebuilts, even ACDelco. Had much better luck with new Chinese ones except from one supplier which doesn't sell them anymore (Prime Choice/AutoShack) and also had bad luck with Remy.

I'm pretty sure the one on there now is a Remy reman.

Was looking at a WAI Global 8292NDR-220A from Rock; runs about $175 (plus the ubiquitous shipping, of course). With that company name, it looks like it would fulfill your Chinesium recommendation... LMAO.
12mo warranty, no more (or less) than any other on their site. If I use my Amex, they'll double the warranty as a perk for having their card.

A 'stock' 145A will run $100-125 USD from Rock. For the coin, and like you mention, those power-sucking fans (3 relays, and they can actually draw 45A (!) if they're both running)... I'm thinking to boost the amperage, since I expect them to be running pretty constantly, in summer heat under load.

And finally, for laughs... here's a screencap of a conversation I had this morning with the guy on CL re: his chromed alt that he's had advertised for $300 for a year (not exaggerating by much, either).

 

[littleblazer]

I used a WAI stator in my cs144. Was a much nicer piece than the stock one and was balanced better... can't comment on their assembled units but the parts seem to be delco service grade equal.