In testing my alternator this weekend, I can see that the output is beginning to get weak, sometimes I see it drop below 14.4 volts, sometimes it's good. It's starting to provide some noises as well, so I'm going to replace it.

I have searched and seen countless posts on the "95" and "130" amp alternators, some mentioning the 4.0 being a direct bolt for the 3.0, some saying one bolt won't line up, some saying the pulley is different (larger/smaller), and the list goes on. I also see that there was a 130 amp alternator used in some 2000 Ford ranger 3.0 V6's, but I cannot seem to find a part number for this option alternator.

So, do I insist that my parts person find one (he states only the 95 amp is offered), or can I use another alternator from an Explorer or ?

Looking for a direct bolt in, no belt changing, no pulley swapping, just a bolt in.

 

If your alternator is outputting 14.4v all the time then you have another problem.
After startup you should see 14+ volts until battery is recharged from cranking engine, so 2 to 5 minutes.
Then voltage should drop to below 14 volts, 13.5-13.8v, it should be about 1.1v above battery voltage(with key off).

I.E. if battery voltage is 12.5volts with engine off, then after initial startup recharge, the "maintenance" charge should be 13.6v, this voltage maintains the battery's 12.5v without damaging the plates.
Constant 14+ volts will shorten the batteries life.

Constant 14+ volts will happen if voltage regulator is failing or if battery is nearing it's end-of-life.
New battery has 100% life and 12.8volts
3 year old battery has 75% life and 12.5volts
5-6 year old battery has 50% life and 12.2volts

When a battery hits 12.2 volts it will probably not start engine on cold morning, chemical reactions are slowed down with lower temperatures so battery can not discharge enough Amps fast enough to turn starter with only 50% life, the dreaded "click, click, click".

You should measure engine off battery voltage after battery has been sitting, unused, for a few hours.

Alternators and amps:
Factory alternators have enough amps to run all factory options with a little to spare.
If you are adding electrical non-factory options then going with a high amp alternator would make sense, otherwise there is zero benefit.
Light bars
Winch
2,000 watt sub woofer
These would require extra amps, but.......a second battery is always a better option, but harder to install.

To test alternators amps, start engine and let it idle until voltage drops to the mid-13volts
Once voltage is stable start turning on the electrics
Head lights
Fan blower to high
stereo
Ect.........

The voltage should drop with each power draw then come back up to mid-13volts, this is the voltage regulator doing it's job.

If the voltage drops to low 13's then one of the "fields" in the alternator has failed.
There are 3 fields that generate AC Voltage, and each field has 2 Diodes that convert this AC voltage to DC voltage.
Common sign of a failed field is the headlights dimming at idle, at idle speed the alternator needs all 3 fields to maintain enough amps to maintain the mid-13volts.

Yes, the 130amp alternator was a Ranger option from '96 to '03
The 95amp alternator has smaller case and longer support arms(where bolt holes are located)
The 130amp-200amp, has larger case and shorter support arms so they are a direct fit.
The 130amp does have a smaller pulley but tensioner will take up the slack.

 

I have the 130amp alternator on mine to power the e-fan. But up until that was added the factory alternator had no trouble power my small amp and sub and duble din head unit as well as expo OHC and HID ballasts. It wasn't until that plus the e-fan addition that it started to struggle. If you plan to add other stuff it might be good to go ahead and upgrade. Any more than 130amp you will need to do wiring upgrades. I just went to the parts store and asked for an alternator for a 4.2l v6 f-150 and it was a direct bolt in with exact mounting points.

 

My concern is that I installed a Ford 2 speed fan from a Mark VIII (used to be in my 2005 F-150). The high speed will kick on at around 195 - 200 degrees (the two speed controller I use allows adjustment for this). When this high speed kicked on initially, it was popping the high speed fan circuits 30 amp relay on the controller. I called the manufacturer of the controller (Ron Francis; great folks, great controller) , and they sent me a 40 amp relay to wire into the second speed fan circuit, using the 30 amp high speed circuit essentially as the "trigger" to operate the 40 amp. This was due to the second speed on this fan drawing a bit over 30 amps to 'start up'. The folks at Ron Francis were aware of this, and were very helpful to get me fixed up. They were willing to replace my controller with one they had that used a 30 amp relay for the low speed, and a 40 amp relay for the high speed.

So, with the A/C on, the low speed fan cycles on, and all is well. When the engine tempurature gets to around 200ish, the high speed cycles on, and its this load on the 95 amp alternator that has me concerned, especially if I'm idling for a period of time, and perhaps at night, with the headlights on.

Since the truck has 216K on it, and all indications point towards this alternator as being the original, I figured I'd do some preventitive maintenance on the charging system and replace the alternator, rather than wait for it to fail. The battery looks to be an older one, although it's still cranking the engine.

Anyone have any information on the 130 amp alternator that was offered as an option for the 96 to 03 Rangers? I've tried two different automotive parts stores, and neither can find a listing for one; all their listings point to the 95 amp only. There is a NAPA store I can go to, but its a good 30 to 45 minutes away from me. They always seem to have better equipped parts folks to help out.

 

Have them look up the 4.0l instead of 3.0l for your model year.

3.0l had the option but it won't be listed.

Yes for the E-fan the higher output alternator would be a good upgrade

 

Yep 4.0l and 03 f-150 with 4.2l v6 with both have a 130amp option that will fit.

 

Gee, you'd think the folks that write the cross reference for the parts guys would get this right. I fully understand that there are a kigillion amount of parts out there, but it also makes sense that Ford (and others) use a same part across the board for many models and years.

Thanks guys. I have one on order.

 

Its actually really hard for them to cross reference that stuff most people who go in there aren't looking for upgrades they simply want a direct fit replacement for what they already have. I have a pretty good relationship with my parts guy and he's into modifieds to so he knows a good bit about what will and won't fit. But for the most part they can't justify the cost of paying their catalog guys to do the cross referencing when only a handful of people actually need that. Best bet is to find a knowledgable guy that knows his stuff and stick with him. We share knowledge at my store and I'm on first name basis with all the guys in the store. I've even answered sales call questions while i was in there before and they bend over backwards to help me. Its all about finding a good one and having a good relationship with them.

 

I can understand the few that wish to upgrade, and can't expect the parts folks to know cross reference, but what about the point that a 130 amp was indeed an optional alternator for the 3.0 Rangers during certain years? There should be both a 95 amp, as well as the optional 130 amp alterator listed in this case.

No worries. I'll suppose someone who purchased a ranger that came with the 130 amp and then had it replaced, and got a 95 amp would not know the difference, so its a moot point.

 

Yeah from what i read the 95amp was the standard and if i had to guess id say the ones with the 130amp were kinda of a whatever was laying around at the plant kinda deal. But who knows they do lots of quirky things when they build cars.

 

Yes, this is true. I had an annoying door rattle in a brand new 1986 Cutlass I had purchased. Took it to the dealer under warranty; they found an empty soda bottle inside the door!

 

Yeah 70's and early 80's were notorious for that stuff. Ive seen two identical early 80's broncos with not only trash in the doors but things under the carpet and being identical you'd think all the bolts and things would be the same but no dice that had all kinds of random fasteners holding stuff on. But can't say i completely blame them at least on the fasteners best business method is use what you've already bought. Guess your cutlass builder thought you need some extra insulation lol

 

He shoulda put some fiber in the glass bottle....presto! Fiber glass!

 

Maybe find a place that has both in stock... just put them side by side and see if the holes are in the same place.

 

Well, the one I finally got, rated at 130 amps, is labled "heavy duty", and is a remanufactured. However, the housing has the 4 holes, and not the two. I was assured it was 130 amp, and not 95 amp.

 

I just thought I'd add a little info here. I work at Autozone and I had a chance to pull both the alternator for my 2005 and the one for like a 2000 F-150 with the 4.2.

As you can tell, they are nearly identical, the mount holes all seemed to line up. A much better option for an upgrade since it comes with a Lifetime Warranty unlike many of the similar ones on eBay.

 

STAY AWAY from the ebay ones tried that first and the voltage regulators are crap even with very little strain (no accessories other than lights) my headlights would surge with rpms. I suggest going new to start to save headaches because the price difference is minimal.

As for the OP the hole count really only applies to OEM units remans only reuse the case usually most of the internals are replaced so its possible to have a 130amp in a 95 amp case seems kinda screwy but I've seen worse lol

 

This appears to be my case (no pun intended).

Good info on the 4.2 being a swap for our Rangers.

 

The swap corrected my problem. Dash cluster guage shows charging slightly above halfway mark; lights at night are noticably brighter as well.

 

Go to motor crafts website you have plenty of decently priced options there.