Had the batteries individually load tested this morning and they both checked fine. They were both replaced about 1.5yrs ago. They are Wal-Mart's brand. The first alt I installed was a new 140amp from the Zone and the one installed yesterday was a reman. Even though batteries tested good I am contemplating taking a drive over to Wal-Mart to see if they will replace. I guess it's possible also that the reman alternator diode was junk out of the box as well.

Matt

 

I too have walmart batteries....about 1.5 years old, I was thinking the same thing, let us know what they say at wally world please.

 

Well I can tell you wally world wouldn't replace since they load tested good. I even tried playing the card that since I have "Northern Batteries" but that didn't work either. What I did find interesting though is that on their computer it recommended the 65S series which "s" stands for southern but they are only 740cca. If they would've had a big enough battery on the shelf I probably would've bought them. I am at a loss with this. Alternator and batteries load test 4.0 however driving tonight I was seeing anywhere from 12.7-13.3 via obd. Have never seen numbers that low after glow plugs kicked off in the past 5yrs of owning truck even when I had the 110amp on there. I hate throwing parts at it so I just keep reassuring myself that there is anywhere from a .2-.5 voltage drop at obd and that at least it's not in the 11's which would indicate not charging at all. I also now have blown a clamp on turbo intercooler pipe so my truck is currently sitting on the side of the highway headed out of Vegas. If it wasn't for bad luck I wouldn't have any right now. Guess it's a good thing I stayed out of the casinos!

 

I've got Walmart Maxx batteries that are about 2 years old and they have been tested three times during the last 6 months due to my FICM dance and those are good batteries, always test above rated capacity. I wouldn't be worried about the batteries.

I don't care for those voltage numbers either. I also never buy electrical components from the retail stores, especially rebuilt. I've been to locations that do the rebuilds for them.

I would pickup a voltmeter so you could check OBD vs battery readings so you have a better handle on what's going on. Years ago I picked this power port meter for when I was looked for a used car for my granddaughter, and I've used it successfully in other vehicles to quickly checking out issues before getting deep.

 

From my experience those numbers should equate to a real reading at the battery of anywhere between 13.2 - 14.3.

Those numbers look good to me.

 

I don't care for those voltage numbers either. I also never buy electrical components from the retail stores, especially rebuilt. I've been to locations that do the rebuilds for them.



I would pickup a voltmeter so you could check OBD vs battery readings so you have a better handle on what's going on. Years
ago I picked this power port meter for when I was looked for a used car for my granddaughter, and I've used it successfully in other vehicles to quickly checking out issues before getting deep. [/QUOTE]

I don't particularly care for the numbers either to be honest with you which is why I am trying to find a reason for it. I have a volt meter and when I swapped out the alternator the other day I was reading 14.2 at the lug on the back, 13.8 at the batteries and 13.3 on the ScanGauge. Until Friday after driving 13+ hrs I have never seen readings that low coming out of the obd. Now I have seen them with a new alt that all of a sudden went **** up, maybe and the reman I got as a warranty swap. There has to be an underlying reason for it to now be reading that low. The reason I buy from the retail places is because they're on darn near every corner of every town. I purchased the original alt in Washington and it was warrantied in Vegas. Sure it's a roll of the dice what kind of product you're getting, but it beats having to take it off and send it back to somewhere in order to get it fixed.

Matt

 

For what it's worth when I saw 12.9v on a hot day with ac on in traffic I changed batteries and alt. Just so I could start fresh as I didn't know how old the system was.

 

I can attest to how "awesome" Autozone alternators are....

I went through 6 of them in 5 months before I got one that worked properly. They would do the same thing your alternator is doing and I'd finally had enough. I took it to a local rebuilder, they tested it and found that the regulator was bad. They replaced the regulator and I haven't had a single problem with it since. It puts out 14.2 volts at OBD2 and around 14.5 at the battery.

I recently installed an O'reilly 140 amp alternator on a customer's '03 Excursion and out of the box it put out a solid 14.5 volts. The 6th autozone alternator could maintain a steady 13.5 volts out of the box. The other 5 autozone alternators couldn't do that.

My suggestion:

Get your money back for the Autozone alternator and get yourself a new (not rebuilt) oreilly alternator.

 

I agree on NEW from the big box stores--I wasn't going to trust a rebuild.

 

I don't particularly care for the numbers either to be honest with you which is why I am trying to find a reason for it. I have a volt meter and when I swapped out the alternator the other day I was reading 14.2 at the lug on the back, 13.8 at the batteries and 13.3 on the ScanGauge. Until Friday after driving 13+ hrs I have never seen readings that low coming out of the obd. Now I have seen them with a new alt that all of a sudden went **** up, maybe and the reman I got as a warranty swap. There has to be an underlying reason for it to now be reading that low. The reason I buy from the retail places is because they're on darn near every corner of every town. I purchased the original alt in Washington and it was warrantied in Vegas. Sure it's a roll of the dice what kind of product you're getting, but it beats having to take it off and send it back to somewhere in order to get it fixed.

Matt[/QUOTE] Matt, I agree with your line of thinking and I believe ultimately we have an underlying problem, it's just to much of a coincidence for us to be having the exact same problem ,doing the exact same thing to correct it and having the exact same results all the while putting parts on the truck from different suppliers. My replacement alternator was a NEW 140amp from Carquest and it didn't do enough to correct the problem to say it was worth the trouble. Hopefully one of us will find out what is causing this before it fries the FICM or does harm to the injectors or god only knows what else. I wouldn't be concerned with 13.5 or 13.6 if I hadn't NEVER seen it that low in the two years of owning this truck.....that is the reason I'm watching this thread so closely.

.....and sorry to hear about the truck leaving you on the roadside I hope that all works out well for you.

 

Well the voltage regulator went out completely after rescuing my truck off the side of the road.( turbo clamp departed truck) I stopped by Auto Zone so they could verify, and I told them that rather than a replacement I wanted a refund. Took said refund over to O'reillys and got a new 140 from them. Voltages are still fluctuating a lot on SG, but the lowest I am seeing right now with all accessories on is 13.4. I also let truck idle at operating temp with a load on it and for 5mins the voltage at lug on back of alt was 14.3 and then did same thing watching batteries with their voltages maintaining 13.8/9. Meanwhile the obd is running from 13.3/4-13.8. Now I think my ECT sensor might be crapping out and it appears I developed a leak coming from the rear pinion seal. When it rains it pours...

Matt