4.0L Alternator Question

[Marvin Brooks]

I am having to replace my alternator on my 2004 Explorer. At Oreillys they said there are two different alternators one with a black cover on the back and one without the black cover on the back. They had no idea if the two are interchangeable or not. I got the one with the black cover on the back since I wasn't sure about whether or not the old one had it. Of course I get back and the old alternator doesn't have the black cover on the back. Anybody know if these two are interchangeable or not? I can go swap it out but wasn't sure if I needed to or not. Thanks in advance.

 

[TechGuru]

First thing, don't buy a Oreilly (or AutoZone) alternator, lol. Well since they have a LLT warranty and the alternator is on top and very easy to change I guess it's ok, lol. Personally I'd go with this Bosch reman: https://www.rockauto.com/en/moreinfo.php?pk=1379980

I do not believe they are interchangeable. The black back is To 12/04/2003 and the silver back is From 12/04/2003. Check your door sticker for your manufacture date.

So your OReilly part number is R112079A for the reman and N112079A for the new.

Tip, go ahead and take the old one out before you head back over there for the exchange so you can go ahead and get your core deposit back and not have to make another trip.

 

[Marvin Brooks]

Thanks for your reply got it exchanged and installed it this evening.

 

[imp]

Thanks for your reply got it exchanged and installed it this evening.

@Marvin Brooks
How is it working out? I suspect the main difference between the two alternators is in the connectors which plug into them. Ford official wiring diagrams show an "early build" and a "late build". Electrically, the difference between the two is pretty simple: Early build did not use the alternator "S" terminal at all, whereas Late build had two "S" terminals connected together external to the alternator. Otherwise, the wiring is the same. imp

 

[Coolhand20th]

I have the black alternator on mine. What is the quality like on the Oreilly one you got, warranty and price? I might change mine out in November when I have a little extra $$$ or upgrade it to a 200 amp if I can find a good brand with a good warranty on it and then keep my original one as a backup. So I'm kinda curious as to what you think of the one you got @Marvin Brooks after you run it for a couple weeks. I'm only considering changing mine out because of it being 14 years old and because when I get back from my trip this weekend I am going to be putting in 2 amplifiers and a capacitor for my stereo system. My one problem is if I have to upgrade all the wiring to go up in amperage then I'll stick with the stock amperage.

 

[Mbrooks420]

I have the black alternator on mine. What is the quality like on the Oreilly one you got, warranty and price? I might change mine out in November when I have a little extra $$$ or upgrade it to a 200 amp if I can find a good brand with a good warranty on it and then keep my original one as a backup. So I'm kinda curious as to what you think of the one you got @Marvin Brooks after you run it for a couple weeks. I'm only considering changing mine out because of it being 14 years old and because when I get back from my trip this weekend I am going to be putting in 2 amplifiers and a capacitor for my stereo system. My one problem is if I have to upgrade all the wiring to go up in amperage then I'll stick with the stock amperage.

I doubt you'd need an upgraded alternator. Typically if you have that kind of draw you do the 'big three' upgrade. I had tons of big draw items (4 amps, power inverter, aux lights, winch) in my last Mounty and the 130 amp was always fine.

 

[Coolhand20th]

Ok that was what I was thinking but wanted to make sure, Thanks Mbrooks420. Plus I am curious as to what Marvin Brooks thinks of his after a couple weeks. I'm not having any issues but it's more of it's 14 years old and at least with a new one I have that piece of mind. I'm not adding in a lot of wattage with the 2 amps, 1100 on the PPI Mono Amplifier and then little over 800 on the 4 channel amp for the door speakers. I really don't need a capacitor but it doesn't hurt considering the cost of them.

 

[TechGuru]

High amp alternators are really expensive, it might actually be cheaper to just add a second alternator if you can find a bracket.

 

[Mbrooks420]

Is that PPI vintage?

 

[Marvin Brooks]

I'll have to let you know how it goes, it works fine as of now but it is a reman so hopefully it holds up. I don't have the warranty info on hand but it is an ultima alternator I believe. That was the only one they had in stock without the plastic cover for the Explorer.

 

[TechGuru]

I'll have to let you know how it goes, it works fine as of now but it is a reman so hopefully it holds up. I don't have the warranty info on hand but it is an ultima alternator I believe. That was the only one they had in stock without the plastic cover for the Explorer.

I believe all of their alternators are limited lifetime...

 

[Coolhand20th]

Is that PPI vintage?

No it is not, however all their amplifiers are made by Soundstream and have been for a few years now since they were bought out by them. Their older amplifiers were awesome and while this is not a vintage amplifier with it being the same as Soundstream I'm not concerned about it. Has a 3 year warranty with it from the seller as it is refurbished and I've had them warranty another amplifier I got through them and no questions asked just ship it back and as soon as they get confirmation it was shipped from the tracking number they ship yours. Seller is someone called Stereo Needs on eBay. The PPI 1000.1 looks like the one that says PPI 900.5, called their Phantom series. They have one in the series before that NIB for $130 which is only a few bucks more then what I paid for mine 4 or 5 months ago.

https://www.ebay.com/sch/stereo-needs/m.html?_nkw=&_armrs=1&_ipg=&_from=

 

[Mbrooks420]

I'm sure it's more than enough for what you need. I've just always loved their old stuff. Their Art series 1000 amps used to weigh in at about 60 pounds. Pure muscle. I've been on the hunt for some old school amps.

 

[Coolhand20th]

Same here their older stuff were beasts, same with Phoenix Gold, the 1st series of the Rockford Fosgate DSM amplifiers. I had one of those in the 200.2 bridged out to 2 MTX Blue Thunders original series in a 1993 Chevy S-10 that were loud as hell. I love those old amps they all put out way more then what they were advertised for. Even the Radioshack amplifiers from the mid '90s were awesome they were made by PPI which many people didn't know. If you opened one of those up next to those old PPI's they were exactly the same inside.

 

[imp]

If wiring is upgraded due to larger capacity alternator, all that need be changed is the alternator B+ feed wire size to the Battery (underhood) Junction Box, as the remainder of the wiring is already sufficiently sized, as well as appropriately fused. imp