Out cruisin' around tonight, stopped at a red light. Defrost fan seemed to slow down a bit, so I checked the gauges and sure enough the battery gauge was down quite a bit. It was under pretty good load (wipers, defrost, headlights, brake lights) at idle, and seemed to pick up a bit on it's own and mostly sit where it always has as long as I was driving. Seemed back to OK when I got home...crossing my fingers it'll hold together through this week, and a 300 mile pulling a trailer on Friday. For a number of reasons, that'd be a whole lot easier than doing it before hand...

*AutoZone alternators, even the lifetime ones, are JUNK. This will be the third one I have been involved in installing in this truck, and I believe there were two before that. I'm thinking the factory one went out around 70k...so that makes 5 in 180k miles, or one every 36k miles on average, roughly half what the factory one did (and that wasn't too impressive, either).

That sucks. It seems harder and harder to get a quality rebuild anywhere. Is yours under warranty?

You may also want to check the condition of the battery cables and the ground straps. I have heard that too much resistance and/or voltage spikes can be hard on alternators.

It's got a lifetime warranty. If they didn't, I'd be buying higher quality ones... Next vehicle, it's gonna be a Napa lifetime- I hear good things about them, and Napa stores are easier to find in rural areas, in my experience.

I'm pretty sure we took a lot of life off this one when we installed it; the battery was nearly dead from driving home after it quit, then the truck sat for a while because the tensioner snapped (road salt eats aluminum...). Threw a trickle-charger on it overnight, but I guess it wasn't long enough because it acted like the battery was kinda low for the next three days.

Maybe I ought to look at my battery, too...it's got to be close to 6 years old, now.

A weak battery can also shorten an alternators life. May be worth checking into.

On a side note, 6 years is amazing. Down here we're lucky to get 3. I guess from the heat is what I'm told.

Auto Zone engine parts ain't worth the box they arrive in. Trust me.

First chance you get, swap that guy out for a top end NAPA or FoMoCo alt.

I can't really defend th AZ pieces too much, but I will comment that I don't get an exceptional amount back on warranty. They used to be absolute trash, but at this time, since they are even cheaper for me, I have started using them, and haven't had any issues yet personally. I will recommend avoiding the Valucraft line for certain, those are failures waiting to happen, sometimes right out of the box, they are trash.
Weak/low batteries are hard on alternators, as well as heavy loads regularly on the charging system. Typical true life of a battery is 4 years, and heat/extreme cold is hard on batteries. Voltage spikes from loose connections and resistance from corrosion can cause problems as well. I do notice more common problems from the Ford alternators, GM is worse. The wiring harness seems to be a problem with Ford alternators. They get loose, then the voltage spikes will cause the diodes to fail.
Like I say, I'm not overly defending the AZ stuff I was sworn off their electrical for years before I started there, and that kind of thing was a concern to me when I started there. I even voiced it to them, and the trainer admitted they had a problem with their electrical stuff before, but had finally been working to correct that. Still cheap, but not as cheap.... I can't say switching up to the Gold line would make any real difference either, as supposedly the only thing that is reused is the casing on the lifetime base. I have had troubles with Napa parts even before, so you just can't win... In order to compete, they are all cheapening up. We get so many customers that will pass up on better durability for a few bucks, then ***** because the part fails faster. Too many focus on price but not quality, and that has driven the market to where it is now.

Skandocious said:

First chance you get, swap that guy out for a top end NAPA or FoMoCo alt.

Click to expand...

Naw....one more lifetime one should get this truck close to 300k...if I'm still driving it regularly at that point, I have a feeling she's gonna need a whole lot more than an alternator.

I probably won't BUY another AZ alt, though... part of my thing with lifetime warrantys is finding the store you can get the new part at...in MA, you can't turn around without finding an AutoZone, but as I've traveled around more, Napa looks like the way to go if you're in rural areas, and they're in every fair-sized city I've been in, too.

dont worry i have the same problem with napas alternator chek this out my trucks logbook

ELECTRONIC:
New stock 2 G alternator ( with new fusable link and new harnass ) nov -2007 257.700


New stock 2G alternator replaced under warrenty Juni 2008 261.500


im on my 2nd alternator now

From my (very limited) experience, coupled with the experience of a friend who works at Napa, the only Napa ones worth having are the Gold (or whatever they call the lifetime one)...the one with a shorter warranty is crap.

Watched it again out driving today.

Basically, it reads normal on the gauge unless I'm idling with a couple big-draw items (such as the fan or headlights) turned on. If I've got the fan on high, lights on, etc., I can watch the gauge bounce a little with the blinker. So I've got an issue.

Based on what it does, and what I can measure with a multimeter, how to I tell if it's the battery, the alternator, or both? (Or do I just replace both on principle, since the alt is warrantied, and the battery is old?)

*Also, does anyone think I'm making a colossal mistake trying to run this thing through one more week and then 300 miles after dark with a trailer? I know it's a gamble, but...there's some chances worth taking and some not.

Why not take it in and have them load test it?

Well...there aren't any AutoZones near here, and the only place I know of that does that free is VIP. I will NOT let them touch my truck, because I was once in there and heard them refuse to release a vehicle to a (female) customer because it wouldn't pass it's state safety inspection and they "couldn't" let her drive it out of their shop until they fixed it. That's illegal and immoral (though nothing compared to the illegal actions if they tried it on me). It IS illegal for her to drive it if it won't pass inspection, but that's HER problem, not theirs.

I gotcha.

the only other thing I can think of is. Take a reading ER lights, fan, etc off then compare it to a reading w/ a full load and see what the drop is.

A quick check would be to hook up a DVOM and see what the reading is with it running no load, and compare it with a load. It should not drop below 13 volts. Your ranger may not be so bad, but many newer vehicles have to have a good battery to be able to keep up with the higher loads, because the alt can't do it alone.

Shoot I've done an altenator on a Ranger that would do the same thing, had a bad voltage regulator on it...you might be getting crappy VR's on the alts.That'll do it too.

I gauge bounces very slightly with the blinker too... Never thought it was too much of a concern, mostly does it with the efan on. Should I be concerned?

I wouldn't, seen in many times on many brands. If you think of it this way, it isn't a concern: Your turn signal makes a sudden change in load, then releases it, so the voltage SHOULD change accordingly. If it were to drop and stay dropped, then you should be concerned. There is much more load on these alternators than even in the early 80's.

It wouldn't be a concern...if it weren't for the fact that it's also about 25* lower than it usually sits. (Also, it never did it before, and it's swinging WAY more than is "normal.")

New alternator is in. Have to see how it works over the next few days...the needle was swinging a little more than it used to, say, 6 months ago, but the battery may be discharged from the old alternator.

I may throw a new battery in before it gets cold, too, just for good measure.

From my personal experience the brushes are the first thing to go on an alt.
They are cheap and easy to replace.
When my battery cables are corroded my volt meter does a lot more moving.
A weak battery will also cause that.