I think it's the alternator

[6716]

So a couple of weeks ago when I started up the battery light stayed on longer than the lights do at start up and it wasn't until I started swearing that the battery light went off, and I figured it had learned its lesson.

Lately I have noticed erratic voltage. Lights dim when I come off the throttle. Within the last couple of days, right after startup, the voltage stays low, like around the has mark between the 9 and the 14, but then keeps lowly dropping, until I hit the gas hard once or twice, and then the voltage jumps up towards 14 and the fan blows harder and the lights come up.

Tonight it was slow to jump back up, and as the voltage continued to drop, the ABS and Parking Brake lights came on. And then the voltage jumped back up, and those lights went off.

And the battery light hasn't come on since that once.

The battery is new as of August 28 and is the model in this thread: http://gmtnation.com/forums/threads/are-more-ccas-necessarily-better.14148/#post-457759

The alternator is a Delphi from Advance Auto Parts and installed on Feb. 15 of this year.

What do you think?

 

[djthumper]

Have it tested but also check your ground connections.

 

[6716]

Have it tested but also check your ground connections.

I wondered if it might be a ground.

I'm looking at pictures of the ground locations ... is any one ground more likely a candidate than another, do you think?

 

[roughtony]

How about the voltage regulator?

 

[AtlWrk]

Or the 2 wire connector to your alternator? A cracked "generator turn on" wire from the PCM can cause the alt to sporadically shut down, which sounds like what's happening.

 

[littleblazer]

I wondered if it might be a ground.

I'm looking at pictures of the ground locations ... is any one ground more likely a candidate than another, do you think?

The ground from block to frame may be a good starting point. It runs directly to the battery as well.

 

[Mooseman]

I had a couple die on me just like that. On/off/on/off until it eventually died.

How about the voltage regulator?

It's built into the alternator. I haven't seen a separate regulator since... the early 70's.

 

[Capote]

I shared some of those similarities when my alternator was going bad, check everything stated above, but my bet is its bad.

 

[6716]

Thanks everyone for your thoughts. I have some time tomorrow in the daylight and I will start to take a look at the grounds.

So I drive a lot for work, so I have had a number of start-ups today.

Usually when I shut down and start up I have the fan blowing at whatever, usually at the full 5 mark at this time of year.

Today, though, I consciously turned the fan off before starting up, and on five consecutive starts I have not had that problem. When I turn the fan on, there is a noticeable drop in voltage on the meter, which ultimately bounces back. Any connection anyone can think of on that? Does that lead to a specific ground?

Last random thought (for this reply) ... I dropped the bottom bolt for the alternator dong the re-installation 10 months ago. It never dropped out, I bet it's still on board, but it never did get installed. I'll check the snugness of the upper two bolts but that shouldn't contribute would you think?

 

[Mooseman]

It's normal for the voltage to drop a little and bounce back when a heavy load, like the fan, comes on and the alternator catches up to the load.

Although the missing bolt won't make a difference as far as electrical load is concerned, you should replace it just so you don't stress the upper mount.

 

[07TrailyLS]

Just a thought. That missing bolt may be letting your alternator move the slightest causing your belt to skip. And just a side note, I've noticed the last 5 or 6 new threads primarily deal with alternator issues. Dumb luck or that time of year idk just had to throw that out there

 

[Mooseman]

Could be the use of heaters and the rear defrost that's pulling more amps. Don't forget that using the front defost above freezing kicks on the A/C so you could possibly have 3 high amp loads on.

 

[Ziggy]

I would tend to agree, I suspect the voltage regulator in your alternator isn't doing its job properly. Anecdotally, years ago, before Advance Auto Parts bought out Trak Auto in Northern Virginia, I bought a reman alternator from them with a 1 year warranty for my '86 firebird. I got warranty replacements for that alternator for 4 years because it seemed they would crap out every 10-11 months. I got really good at swapping alternators in that car. It was the same thing though, started noticing my lights would dim at idle, then brighten up when I gave it a little gas. Integrated voltage regulators on their reman alternators were quick to crap out it seemed.

 

[6716]

I would tend to agree, I suspect the voltage regulator in your alternator isn't doing its job properly. Anecdotally, years ago, before Advance Auto Parts bought out Trak Auto in Northern Virginia, I bought a reman alternator from them with a 1 year warranty for my '86 firebird. I got warranty replacements for that alternator for 4 years because it seemed they would crap out every 10-11 months. I got really good at swapping alternators in that car. It was the same thing though, started noticing my lights would dim at idle, then brighten up when I gave it a little gas. Integrated voltage regulators on their reman alternators were quick to crap out it seemed.

Did you just go in and say you wanted a new one? Did they test it there? Did they just give you a new one? Did you swap it out right on the spot?

I could drive there and make the swap in 20 minutes in the lot.

This morning I made sure every draw I could think of to shut down was off. Voltage went pretty straight up to just under the 14 mark. So no issue. Which makes me wonder if it is the battery. It is the component most recently changed, and I didn't have this problem before the switch.

How would I prove or disprove the battery?

 

[Blckshdw]

How would I prove or disprove the battery?

Get it load tested.

 

[mrrsm]

You did not mention if you have a towing set up with any after-market harness installed and I was wondering whether or not your High Quality Delphi Alternator puts out as much Stable Amperage at 1,200 RPM as THIS one claims to perform at and still deliver the promised level of 250 AMPS at that engine speed:

https://www.powerbastards.com/products.asp?cat=142988&navsid1=20&navsid2=99

 

[6716]

You did not mention if you have a towing set up with any after-market harness installed and I was wondering whether or not your High Quality Delphi Alternator puts out as much Stable Amperage at 1,200 RPM as THIS one claims to perform at and still deliver the promised level of 250 AMPS at that engine speed:

https://www.powerbastards.com/products.asp?cat=142988&navsid1=20&navsid2=99

That is nice equipment.

Actually, I think I have a remanned AC Delco from O'Reily, now that I look into it.

I'm going to go after a warranty replacement on mine, but I might put that powerbastards alternator on the wish list. I don't have any additional sound or lightbars, though I would like to add an inverter and a second battery at some point, and that would be the generator to go with then, for sure.

 

[6716]

Four grounds seem to check out. The ground on the body between the battery and the fuse box, the one a little closer to the interior on the body, the one on the driver's side firewall, and the one on the block. Well, I put a flashlight beam on the one on the block. It doesn't look any different than the others, no corrosion, they all look snug.

 

[mrrsm]

There IS one other mysterious electrical event that I've held back regaling everyone about... and it has to do with the Tail Light Triple Light Circuit Bar that holds the three bulbs... melting and shorting out. I literally had months of 'Chasing the Dragon of Electricity' 'round and 'round with Dead Batteries (High Dollar Yellow Duralasts) and endless failed starts... until I got a stronger non-OEM non-REMAN Alternator that would not relent against the drain of power and amperage on the Battery... and at the same time... I replaced both of those Triple Light bars...and this is the most important part:

I FILLED UP EACH LIGHT SOCKET TO THE BRIM WITH LUGUBRIOUS AMOUNTS OF DIELECTRIC GREASE. After that... No more incidents of Shorted Out Triple Light Bars or having a Dead Battery occurred. Not one! So If nothing else... if you get a chance to examine your Tail Light Triple bar Internals and happen to find any Burned Sockets... you might want to try this approach out and see if it helps.

 

[6716]

It was the voltage regulator. Tested bad on the vehicle, tested bad off the vehicle, and they replaced it on the spot.

roughtony was the first to call it.

My volts were immediately up over 14 with the new one.

The crazy thing was the ground wire connection had been arcing -- the boot was all chewed-up looking and the hold nut didn't come off nicely. I don't know if that was a cause or an effect.

It was O'Reily's Ultima brand, bought for $149.00. The one that crapped out was a remanned Delphi. The new one doesn't have any marking on the cover. I got about 10 months out of the remanned Delphi. Maybe I'll follow Ziggy's strategy and get a new one every 10 months, or maybe I'll put a nice one on the wish list.

 

[Mooseman]

I've had lots of new and remans crap out on me.

-Prime Choice new: Lasted only a couple of months. They don't sell alternators anymore. They were new from China. Got a refund because I got the Remy on a weekend.
-Remy New: Lasted about 6 months. Because I bought it in the US, it was impractical to return. Peeled a sticker back and it said built in China.
- ACDelco reman: Bad out of the box. Wild voltages all over the place.
- Some house branded new bought at Benson Auto Parts: Looks to be built in China. So far has lasted two years.

Next time, I'm trying a local rebuilder or used from the pick-a-part.

 

[therealsethallen]

I've never replaced an alternator on one of my vehicles. Granted I've owned only Volvos, and the alternators on the 1999-up models are pretty reliable. I've never actually heard of one going wrong.

I put a junk yard one in an Envoy XL last week, works fine.

 

[littleblazer]

I rebuild the one in the vette. It was a Napa rebuild. I ordered the kit it was like 20 bucks, replaced the diode trio and regulator and battery voltage holds a steady 13.8 with a/c on, defroster and efans blasting. The headlights start to pull it down but it is only a 90 amp alternator. And the fans aren't supposed to be on all the time. So I think it's good. The new ones aren't as serviceable. Replaced the one in the escalade with an autozone reman and it's been good. Replaced the one in the sierra with a pepboys reman and you floor it and it just stops charging and pulls down battery voltage. There is no real good rebuild, just luck of te draw. The nice thing about the sierra is that at idle it whines like a blower.

 

[6716]

The more I think about it, I think that alternator was bad to start.

I immediately had belt noise where I hadn't had any before. And the volts were always low, but I didn't actually know what the system *should* be running at, so I didn't pay attention to that. I'm fairly certain now the lower voltage output was what finally put my last battery into failure due to lack of charging.

If/when this one craps out, it would be interesting to open it up and do the rebuild kit littleblazer mentioned.

Omitting the lower bolt sure makes it easier to replace that sucker in the snow in the parts store lot. Not that I'm recommending. Just that I'm noticing.

 

[mrrsm]

I rebuild the one in the vette. It was a Napa rebuild. I ordered the kit it was like 20 bucks, replaced the diode trio and regulator and battery voltage holds a steady 13.8 with a/c on, defroster and efans blasting.

This seems like a very worthwhile thing to know how to do... and this link to a crystal clear visual Step-By-Step How-To-Rebuild-An-Alternator seems like it might be helpful to anyone with a mindset to take one or two off of them off of 'The Shelf of Broken Items" and tear into them in order to demystify how it is all properly done.

http://www.wikihow.com/Rebuild-an-Alternator

I have lived at one time of another along both The Atlantic Coast as well as The Gulf of Mexico and as such, very salty sea breezes get on and inside of everything. You can always tell who the Beach Bums are by the presence of hole-ridden brown, rust cancer dripping from the bumpers and wheel wells of cars that have made one too many trips down the hard sands of Daytona Beach.

It follows on that when Alternators go bad down here in Florida, removing them often reveals swollen, corroded messy things that look long in tooth and much the worse for wear. Because of this... even if you could construct your own set of Reliable Dual or Triple-Rectifiers and substantially robust Voltage Regulators from available modular rebuild components... risking spending any time and money on something with questionable odds on whether the Copper Windings have been Cut, Corroded or Broken deep inside, might seem like more trouble than it is worth.

Nonetheless... building a special Bench-Mounted Serpentine Belt Drive set up... powered by a Rheostat Controlled Electric Motor energized off of a 20 AMP House Circuit to test repaired, Bench Mounted Alternators at specific RPM using a bank of 12 Volt Car Headlights to test their drain on performance... was and still is, a very appealing project I want to investigate.

 

[littleblazer]

The more I think about it, I think that alternator was bad to start.

I immediately had belt noise where I hadn't had any before. And the volts were always low, but I didn't actually know what the system *should* be running at, so I didn't pay attention to that. I'm fairly certain now the lower voltage output was what finally put my last battery into failure due to lack of charging.

If/when this one craps out, it would be interesting to open it up and do the rebuild kit littleblazer mentioned.

Omitting the lower bolt sure makes it easier to replace that sucker in the snow in the parts store lot. Not that I'm recommending. Just that I'm noticing.

You'd have to look hard for a rebuild kit for our alternators... the kit was made by victory lap, and it's not all that hard to do. I didn't replace the bearings though since, like I said it was a reman from Napa put in buy the previous owner. It's had maybe 3k miles put on it in the 8 years we've owned it. It's only a couple of hour job, just make sure you have an ohm meter to check the windings for shorts.

 

[Ziggy]

Did you just go in and say you wanted a new one? Did they test it there? Did they just give you a new one? Did you swap it out right on the spot?

After the first warranty replacement, I just started pulling it and taking it in. The store was only a mile or so away, and they strapped them up to their tester there in the store. Keep your receipts, and any documentation of the warranty.

 

[coolasice]

You'd have to look hard for a rebuild kit for our alternators... the kit was made by victory lap, and it's not all that hard to do. I didn't replace the bearings though since, like I said it was a reman from Napa put in buy the previous owner. It's had maybe 3k miles put on it in the 8 years we've owned it. It's only a couple of hour job, just make sure you have an ohm meter to check the windings for shorts.

You'll need a solder gun to separate the rectifier and housings... kits are roughly $40

 

[mrrsm]

This seems like a very worthwhile thing to know how to do... and this link to a crystal clear visual Step-By-Step How-To-Rebuild-An-Alternator seems like it might be helpful to anyone with a mindset to take one or two off of them off of 'The Shelf of Broken Items" and tear into them in order to demystify how it is all properly done.

http://www.wikihow.com/Rebuild-an-Alternator

I have lived at one time of another along both The Atlantic Coast as well as The Gulf of Mexico and as such, very salty sea breezes get on and inside of everything. You can always tell who the Beach Bums are by the presence of hole-ridden brown, rust cancer dripping from the bumpers and wheel wells of cars that have made one too many trips down the hard sands of Daytona Beach.

It follows on that when Alternators go bad down here in Florida, removing them often reveals swollen, corroded messy things that look long in tooth and much the worse for wear. Because of this... even if you could construct your own set of Reliable Dual or Triple-Rectifiers and substantially robust Voltage Regulators from available modular rebuild components... risking spending any time and money on something with questionable odds on whether the Copper Windings have been Cut, Corroded or Broken deep inside, might seem like more trouble than it is worth.

Nonetheless... building a special Bench-Mounted Serpentine Belt Drive set up... powered by a Rheostat Controlled Electric Motor energized off of a 20 AMP House Circuit to test repaired, Bench Mounted Alternators at specific RPM using a bank of 12 Volt Car Headlights to test their drain on performance... was and still is, a very appealing project I want to investigate.

Not to HiJack this thread... but to amplify the last idea I had for the means to Test our Rebuilt Altermators, I think this guy is onto an interesting way to build a Bench Mounted Alternator Test Machine... (He has modified a Washing Machine Single Phase Motor with Neodymium Magnets to act as the means to charge a powerful Capacitance Discharge Battery):

 

[mrrsm]

I was poking around on another issue and found this On-Topic Video where the Dude does a Bearing Rebuild... right there on the spot as soon as he gets the Alternator unbolted from the "Generic Vehicle"... Kinda Cool to watch, Actually: