Alternator help…

On my 1996 chev k1500 my alternator is giving me some issues.

It sometimes won’t charge above 12.5 volts and most of the time will only see 13.9 volts. Sometimes I get fluctuating lights. Generally my battery will not stay fully charged I have been keeping a charger on it here and there to help keep things going.

I don’t believe it’s the battery because it never dies it just won’t fully charge off the alternator. Although It’s about 5 years old so it probably wouldn’t hurt for a new one but I believe the alternator will be first

The alternator that is on it is a Delphi 105 amp alternator I put it on roughly 60000 miles ago and about 11 years ago.

My truck has electric fans and I believe they contributed to its funky behavior. I did a lot of reading and saw that many people have upgraded to a 145 amp from a early 2000s truck which should be mostly plug and play.

So here’s the whole reason for this post. On my 2011 Silverado if I understand correctly is the same style of alternator just with 160 amp rating. Comparing the two the pulleys look to be the same size and it looks like it should fit into my 96 and have all the cables and plugs reach fine with a little modding of the heater line on my 96.

The only difference I see is that my 96 has a 4 wire plug with 1 wire coming out and my 2011 has a 2 wire plug with 2 wires. If I’m not mistaking I believe they can be adapted to work?

I forgot to measure the mounting spacing but eyeballing them they look the same.

I have already done the big 3 upgrade on my 96 with 2 gauge wire. The truck has a stock stereo system and is the wt trim so the biggest draw on it will be the fans.

Is there someone that knows more than I do that knows if this will work or not? I don’t need 160 amps per say but the alternators cost the same so if I’m gonna do it and it will work I may as well go bigger…

What model is your current alternator? I'm expecting it to be a CS130 with external fan, but I don't know for sure. If so, there's a million choices--mostly Chinese and questionable quality.

Photos? In focus, nicely cropped.

What’s wrong with 13.9?

I’ll try to get some later today. It’ has a internal fan.

13.9 is ok but it only reaches that on cold starts. With no load. Any kind of load and it drops. Especially when the fans turn on.

I was looking at a ac Delco gold unit ad244. The pic is just a quick one I found to post.

Did you check it at the battery with a multimeter?

13.9 is almost certainly too low. And nowhere here has anyone talked about the actual amperage output of the troublesome alternator.

I'd have expected 14.2, perhaps higher voltage. A clamp-on amperage probe is the usual method of determining alternator amperage output.

Would be worthwhile to measure the AC voltage while you're in there.

First Guess: All you really need is an OEM alternator that actually works right. But as you said, as long as you have to replace it, you might as well upgrade. Beware "new" Chinese alternators. I'd rather have a "good used" OEM Delco, or a quality rebuilt OEM Delco, than a brand-new Chinese knockoff.

Internal fan would not be a CS130. The original CS130 was a piece of crap. I've heard good things about the AD240, but i have absolutely no idea about interchanges.

Can't you simply disable remove your efan setup to check for voltage? Remove the relays? See what the difference is with efans running vs not...

I've only run late Vortec 4.3/5.7 and the early LS 5.3/6.0, which I thought were the same? Only in stock form, not mods, e-fan conversion or anything...so that's my background. The times that I've had them fail (2 of them by now on 4 different trucks,) they simply die: checking for voltage gave me a ghost number, like 0.3V IIRC. 1 that died was OEM and 1 looked like a cheap remanufactured unit.

Any of these will work for you. the 105 amp can produce 70 amps @ idle. I assumed a 350 engine. I also selected 1 wire capable for a no hassle install.

105 amp AD230 is not the same size as an AD244. If your truck has the two ears and a back brace or just the two ears at like 7/8 and 4/5 o clock then it probably will fit if you make sure to ensure the ears are the right space. if its an ad244 it possibly might be beneficial for a backbrace. I dont know what you have now or what it looks like, can you show us? It should be either a CS130 or a CS130d if stock and not a HD charging. 105 amp would fit that bill. a CS130D has the same plug as a AD230 and it also has many similar features and, importantly, it has a few more/reliable. Your truck with a 2 pin is a AD230 and you either need a modulator which can be bought to PWM control its charging or you will have a very very low output barely gets out of its own way alternator on your truck despite being an AD244. IF you want to convert it to work without a PWM computer, you need to replace the bridge rectifier with a 4 pin one I believe. But that is solder and some work + a used alternator when you can buy them new or low mileage OEM and get many years. Especially if you dont use yours for high loads.

this is an AD230. Notice the no external fan, it has 2 internal ones(2 in AD230 is 2 fans)
CS130D i believe has one fan but its also internal, i may be wrong, but its why the black cover is on the AD230, it moves the parts to a shrouded area where the fans more efficiently cool the whole unit. CS130 are notorious for poor cooling behavior.

actually, I just googled that pic may be a CS130D. the difference can be easily distinguisehed by the Openings on the case and the rear view of the back with the black cover off usually. The units sometimes shared external designs its a little messy.

they both use this 4 pin Metripack

An external fan cs130 uses this

Frank Enstein said:

Any of these will work for you. the 105 amp can produce 70 amps @ idle. I assumed a 350 engine. I also selected 1 wire capable for a no hassle install.

Click to expand...

An AD230 can produce better than a CS130 and with less heat at the idle. output overall is the same so 105