Alternator Upgrade : Nippondenso 90/120/140/etc Amp

[74Dusted]

So your factory 35 Amp Mitsubishi Alternator sucks and can barely keep up with your headlights, heater and windshield wipers running at the same time? The Internal Voltage Regulator crapped out and now the truck isn't charging? You could buy a replacement alternator, exactly like your old one, but why?


Enter the Nippondenso Alternator, found on Dodge Caravans with the V6 engine and Dodge Trucks (1988 - 2001) with the 3.9, 318 and 360 TBI engines, Magnum V6 (3.9L) or Magnum V8 (5.2L / 5.9L). The lowest output Nippondenso puts out a whopping 90 Amps, many are 120 Amps, some are even higher (approaching 200 amps in some rare cases). The best part, all of them are the same external size and almost identical in size to the Mitsubishi Alternator found on D50 Trucks.


So, how do you go about fitting one of these monsters to a D50?


Step 1 : Find a Nippondenso Alternator (Find a Used One or Buy a New One)

Step 2 : Buy a Chrysler External Voltage Regulator and Pigtail (any chrysler product 1971-1987) For simplicity and guaranteed results on getting the right stuff, buy one for a 1973 Plymouth Duster. This regulator and pigtail are always in stock at every parts store. You'll have about $20 invested in the Regulator and Pigtail.

Step 3 : Swap the Pulley from your Mitsubishi Alternator to the Nippondenso Alternator (because most Nippondenso Alternators have a Serpentine Pulley, some Early 88-91 models have Dual V-Belt Pulleys though)

Step 4 : Loosen your Upper Alternator Bracket/Adjuster Bracket and rotate it up a little bit (about a 1/4" or so). The Nippondenso alternator upper mount ear is slightly taller than the mitsubishi alternator.

Step 5 : Wire up the Regulator Pigtail, connect the wiring to the alternator and add the Ground Strap from the Alternator to the Battery. The entire regulator harness only requires you to connect to 1 Wire from your original D50 Alternator Plug. The Blue Wire connects to the Blue Wire on the Regulator Pigtail (see attached photos).

Step 6 : Mount the Voltage Regulator. The best place is the Passenger Side Inner Fenderwell, about 6" in front of the firewall. There are already bolt holes (threaded) in the fender well in this location. It puts the regulator close to the alternator wiring, as well as the main wiring harness, should you choose an alternate Ign+ Feed

Step 7 : Reinstall your Belt.


http://i182.photobucket.com/albums/x42/ChrisKDD/Mobile%20Uploads/image_zpsdvinehgj.jpg (http://s182.photobucket.com/user/ChrisKDD/media/Mobile%20Uploads/image_zpsdvinehgj.jpg.html)

http://i182.photobucket.com/albums/x42/ChrisKDD/2011-05-13_174014_alternato_zpsfyvqh6bq.jpg (http://s182.photobucket.com/user/ChrisKDD/media/2011-05-13_174014_alternato_zpsfyvqh6bq.jpg.html)

http://i182.photobucket.com/albums/x42/ChrisKDD/alternator-regulator_zpsztpuys3y.jpg (http://s182.photobucket.com/user/ChrisKDD/media/alternator-regulator_zpsztpuys3y.jpg.html)



It doesn't matter which of the 2 small field posts on the alternator you connect the Green and Blue Wires to, the circuit works exactly the same on either posts, but you must have the green on one post and the blue on the other. The Blue wire is the Ign + (on both the D50 and on older Chryslers) which supplies a field to the alternator and + to the regulator, the Green is a pulsed output from the regulator.



Congratulations, you now have a monster alternator that bolts in place of the factory alternator, is readily available at any parts store or junkyard. You also now have an easily serviceable/replaceable and readily available external voltage regulator that can be swapped in under 2 minutes.

The Initial Installation takes about 25 minutes on average, requires no permanent modifications to the truck, and makes it easy to service the charging system with readily available parts.

[pennyman1]

I used to have a 1991 dogkota that the alternator signal from the computer quit working. My friend who owned an alternator shop tried to do this exact conversion on the dogkota, but it would not work right, so he used an external Ford regulator instead. I never had charging problems after that - the rest of the truck is another story.

[74Dusted]

Funny, Pennyman. My Dakota (now a Turbo Diesel...the old 5.2L Magnum V8 donated its alternator to my D50) had a problem with the computer too, and for some reason I had a problem getting the External Regulator Conversion to work on it too.

I fought with it for ages, until (just for laughs) I "borrowed" the regulator from my Plymouth Duster and the truck started charging... The brand new regulator I had bought was bad out of the box.


Technically speaking, the Nippondenso alternator functions exactly the same as the old (60's - 80's) Mopar 60 Amp, 78 Amp, 110 Amp and 200 Amp (Ambulance/HD) Alternators. The only difference (other than appearance) is that Mopar moved the Regulator into the Computer on the 88+ Dodges.... Bad Move, the Regulator in the Computer has been the Bane of Mopar Existence ever since.

You're right though, it doesn't "have" to be a Dodge External Regulator (though it is the easiest to find and is in stock everywhere). Pretty much any regulator that was in use in a Dual Field Application will do the trick.

[pennyman1]

It has something to do with the computer and the wiring, even though it was no longer connected to the alternator. I even gave him 2 or 3 working voltage regs like the one you used - no luck. In our trucks that should not be an issue - just threw it out there in case someone had a problem with the install.

[stockD50]

would this modification work on a 1990 2.4l d50?

[pennyman1]

Absolutely - his directions are spot on!

[stockD50]

well i had a alternator off of a 2000 dodge 2500 5.9 magnum,and not sure if it was a bad alternator or fucked up the wiring, does anyone have a really clear wiring diagram? as im not wiring inclined. and is there a certain alternator out of a specific make/model/year that works better since i have a 2nd gen?

[risingphx25]

I ended up pickin up a 120 amp alternator off a caravan, pigtail and regulator from a 87 dakota for $25.02. Trouble is the pulley on my stock Alternator did not fot the Denso alternator. Had to run back to the boneyard and found a dual pulley set up on an 89 5.9 dodge van. If doing so do not forget the spacer needed on the new pulley. Whole ordeal took 4 hrs but I'm happy finally getting the pieces together.I will be installing everything tomorrow.

[Giovanni89]

I run an ac delco 10si in mine. It is internally regulated and can make use of the stock wiring, but you have to make a bracket to get it to bolt up to the front engine cover. I actually run a 10si in the ram50, have one in the 62 falcon thats not on the road any more, and will be running one in the 68 f250 when I get around to that project. All three have a group 24 battery in them too. Fleet interchangeability is convenient.
The 10/12si are produced brand new in really high outputs as well.
Not quite as cool as as adapting a dodge sourced alternator, but it's been trouble free.

[pennyman1]

That is what Geronimo has a well - ran it for 12+ years until it finally went. Had it rebuilt and back on the road again with better parts.

[risingphx25]

Dang, didnt know the AC Delco was an option. http://imgur.com/gallery/ETjzqSD

[Giovanni89]

Pennyman, mine has been bulletproof too. The only time i thought it was acting up, I had a poor connection.
I'll have to pull mine out and do a write up with the bracket modifications.
http://www.madelectrical.com/electricaltech/delcoremy.shtml has a lot of great info on these, and car wiring in general.

[dash]

what motor ? I fab'd a bracket for a brand new 'small case' GM alternator (97 grand prix?) onto a 2.0 starion motor
alternator shop recommended/supplied it. He made up a simple little pigtail that plugged in.... all for a low price
swapped to a v-belt pulley

google -starquest gm alternator- you'd find many options/installs, for the 2.6
check if starquest accessory layout differ from truck tho
3000GT unit bolt straight on to starion 2.6(+pulley change); http://www.starquestclub.com/forum/index.php?showtopic=26316&#entry226615

[risingphx25]

Quick question. For the B+ terminal I dont have to run a separate wire to the battery do I? I ended up wiring everything the same except no stand alone wire from alternator to battery. Currently is not working charging. Maybe the boneyard regulator is caput. I did ensure to give a ground to the regulator.

[Yoshiwarrior]

Putting an alternator bon that's ablout 3x the size or bigger won't hirt any of the other electrical components or anything, will it? I've got a stereo system in my truck. But I can't even use it because it kills the battery.

[geezer101]

Bigger is always better with batteries and alternators. You will find anything that has a higher current pull will work better (like full car audio systems running amplifiers, the starter motor or decent headlights and driving light combos). The system will only ever push it's peak voltage into the wiring harness and nothing more (13.8v-ish if it's being regulated properly) and the wiring is already gauged for it's respective application. It's when the system is under heavy load/current draw that things can go wrong (recently did an investigation into why my friends' Kia Cerato "potato" was blowing low beams - it pushes 14.45v through each individual light circuit, just bad design from day one...) Most Kias suffer from this issue...a voltage drop and better fuse system and the headlights would last a decade rather than a few months.

[Giovanni89]

I'll just add (not that it has relevance on this board) that you don't want to apply that to permanent magnet alternators like you find in motorcycles. There are no rotor windings to control the output of the stator. They run "full throttle" and the extra watts are dissipated by the voltage rectifier/regulator. An excessively large alternator will reduce the life of the regulator/rectifier significantly. That's why motorcycle alternators are often sized very close to their intended load, and bikes with a bunch of accessories have regulator/rectifiers with huge heat sinks.

[Yoshiwarrior]

Do the Montero alternator have the same size shaft. If I get one of those. And just switch the pulley's?

[85Ram50]

Edit 9-28-20 See post #35 for a synopsis of what I did end edit

There are two pictures I have added of mine, one of all 3 wires and one of the T configured spade connector.

If I understand correct the white wire with blue dashes gets abandoned and I connect the pigtail off the regulator to a field post of the new alt. Then I connect the blue wire to the other field post and splice the pigtail off the regulator into it. I think that white wire is my ground but it may be + wire. Whichever it is do I need to run a wire directly to the battery to be either ground or pos?
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25681&stc=1 http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25682&stc=1

[85Ram50]

I pulled the trigger on a new alt and the pigtail/ regulator.
I still find it hard to believe I have to abandon that wire but surely I should be able to figure out how to make it work.

[Salteen]

Well another option is to install the alternator off a van/conquest with a 2.6. I found one online for $70 https://www.ebay.com/i/382657872596?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=382657872596&targetid=935065066787&device=m&mktype=pla&googleloc=9010411&poi=&campaignid=10880341439&mkgroupid=107912168075&rlsatarget=pla-935065066787&abcId=9300400&merchantid=6331424&gclid=CjwKCAjwqML6BRAHEiwAdquMnTjqdGCxyvyPgO-mqr70-eVnKo2gxnKfMKa0pfx7v3s82f80VQweihoCqfUQAvD_BwE

[85Ram50]

Well another option is to install the alternator off a van/conquest with a 2.6. I found one online for $70 https://www.ebay.com/i/382657872596?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=382657872596&targetid=935065066787&device=m&mktype=pla&googleloc=9010411&poi=&campaignid=10880341439&mkgroupid=107912168075&rlsatarget=pla-935065066787&abcId=9300400&merchantid=6331424&gclid=CjwKCAjwqML6BRAHEiwAdquMnTjqdGCxyvyPgO-mqr70-eVnKo2gxnKfMKa0pfx7v3s82f80VQweihoCqfUQAvD_BwE
I went with one for a Dakota. I'm debating whether or not I should put it on my dakota and used the used one on the ram50. it was $88 for all three parts delivered. It's a pure energy new alt, well if not new they don't ask for a core. I just looked at RA again and they've increased the price by $22 and it says there is only one left. ?!

[Salteen]

If it works that well, pull the trigger. Just seems to me that on most trucks a 90 amp would be sufficient and easier to install

But then again you dont get the bragging rights. The 'unique' rights.

[85Ram50]

The Dakota I have is a 90 amp. You can get them up to 120 afaik.

[85Ram50]

I have the parts, haven't got to it yet. hoping to be able to in a few days.

[85Ram50]

OK I took out the old alternator and started to try to install the new one. I have the feeling I have to eat this alternator and buy another, but not yet. First pic is of the regulator and pigtail for a 73 Plymouth Duster.

The shaft on the 45 amp is smaller, 5/8. The new one is 11/16, so the short bushing off the 45 amp won't work to let the pulley ride on the new one. So I need a new v belt pulley bushing or pulley if the newer ones aren't two piece and have a similar set up to the serpentine pulley.

Next the pivot bolt is 1/4 inch as is the hole through the motor. The holes for the pivot are two sizes, 3/8 and the one with the bushing in the picture is 1/2. How have folks been coping with that?
The top bolt hole is 3/8. You'll need an 1.5" 3/8 bolt with washer and nut for the adjuster. The single bolt on my 45amp won't work.
Except for these annoying but critical differences the sizes look and measure the same. That's 7 inches between pivot and adjuster bolt.
Can't think of anything else right now.
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25756&stc=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25757&stc=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25758&stc=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25759&stc=1

[B-Line]

How are these retrofits holding up for you all?

[85Ram50]

So I was looking for unthreaded slotted spacers. I called and went to several places. No one could help. At the last place the guy, cutting on a huge vertical band saw outside, looks over the alternator and listens to me. Then he says wait a minute. He was gone so long I thought he was pulling my leg. Then he comes out and he has that piece of copper. He told me to take it. It took me a bit to work it out but by the time I got home it sunk in. The OD of the tube was just over 10mm the size of the existing holes. The through bolt is 8mm. Sure enough I cut the tube and it worked. I had to cut it two thicknesses of the cutting wheel on my grinder. Then I cut off the extra spacer that came with it.
I installed it and hooked up the wires and now all I need is to find a V pulley for it. Then I can find out if it works :)
I will eventually move the mounting for the regulator.


http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25760&stc=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25761&stc=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25762&stc=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25763&stc=1

[geezer101]

A low tech solution on a zero dollar budget that works - uber win :thumbup:Fingers crossed it lines up and does it's thing without headaches.

[85Ram50]

A low tech solution on a zero dollar budget that works - uber win :thumbup:Fingers crossed it lines up and does it's thing without headaches.

Best kind of solutions are free. This place never answered me so I pulled the trigger and they charge just $2 less than the price of the item to ship it! I read the return policy and now I know why the never responded, they deduct the shipping fee from your payment on returns. So I mentioned this in my note :) https://store.alternatorparts.com/2481103-1-groove-pulley-for-hitachi-alternators.aspx It looks right but that shoulder height might be off. Maybe I can use a washer?

Note- The spacers did not make it stiff but it did tighten up with no play once I wrenched bolt on. It wouldn't have done that without those home made spacers. I think that was a 1/2" tube of potable water pipe, as it was bent and soft. That stuff has thicker walls than off the shelf hard copper pipe.

[85Ram50]

Still waiting for the pulley. I tore open the wiring harness and pulled the blue wire out of it and retaped the rest. It seems way too small to handle 90 amps. Anyway the heavy white wire runs to the + battery and the blue wire goes into the firewall on the driver side. It is spliced to power the reverse lights. Now if there is a problem I only have to chase it inside the cab and put in a heavier wire.
I saw something on the pulley site. They sell kits for dodge external regulators. Theirs has a clip set up on the pigtail they supply as apparently there is an issue with the plug falling out. So I made one with tie wire.
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=25775&stc=1

[85Ram50]

The alternator parts place was a bust. They never acknowledged my order until 6 days later, yesterday a Sunday when they are closed and it was back dated to last Tuesday. Today they finally responded to my email from Friday asking what was going on to tell me the supplier no longer has that part but they will provide me an excellent equivalent. I cancelled the order. That they did right away. They never did respond to my other email. They have 3 email addresses, they never responded to the info@ email I sent a question to. One an AOL account that comes with the PayPal receipt and two for the website. They may have more.

Edit 9-27-20 bored watching the game (Man did Pollard screw up!) and waiting for parts and looked at RA under belt drive and they have a bunch of idler pulleys. I had thought that was just belts. I assume they are for an AC unit but they have the correct diameter center hole. Wasted two weeks. Oh well I have a double pulley due in this week. Now I know and whoever happens across this in a search does too.

[85Ram50]

Git her dun!

OK the pulley I ordered did not work. I started looking again resentful as hell about the first guy and a wasted days waiting then I just went out there took the pulley from the new alt and cut it up leaving behind the piece that slips over the shaft which was long enough to give me clearance to put the original 45 amp two piece pulley on it with the new nut that came with the alt. I had to pull the alt tighter after the first try as revving it gave belt squeals. I tested the bat before starting 11.99. Then when I had it running and tight 14.90 to 15.03 on the DCV scale of the multi meter. All the dash stuff looked good, radio came right on.
I have to go dump the load in the back then fix the radiator leak. It has been dripping since I tried to squeeze the spot where it leaked to stop it.

[85Ram50]

Loads of not fun excitement.
I could smell gas on the way to the dump. When I was parked unloading teh guy next to me pointed out I was dripping gas. I looked did not see where but knew I could do nothing so I finished and tried to get home as fast as possible. Of course there was road construction. I found it weird it was dripping so fast when it was turned off. I thought the alt had done something to the system and made the pump stay on or something.
I got home and took off the air cleaner, it was dripping just as fast and I finally saw it. The silicon cap I had placed over the return line had melted. I had just recently learned that silicon does not hold up to gas. I found a black probably rubber cap and sealed it. I need to get a fuel resistant cap.

[85Ram50]

Wrapping this into one post.
This method is not what it claims to be. The wiring is correct, the advice not so much. Be careful that what alternator you choose will fit.
On my first gen D50 the pivot bolt is 8mm. If you go with an alternator for a Dakota which I did purchased new, that hole is much bigger. I used a home made solution in a previous post of a 1/2" copper pipe cut to act as a slotted spacer. Had to cut down the width of the slotted spacer it comes with. It feels loose but tightens up nicely when you bolt it down.
The other problem is the pulley on the OE alternator cannot mount directly to the new one for a Dakota. Check the bore sizes and clearances before you decide what you are going to do. Some pulleys have shoulders and the Pure Energy alt I got has an indent that will make the body rub on most pulleys. I ended up cutting the pulley off the new one down to just the part that fit on the shaft. It acted as a 3/8"thick washer and I was able to use the two halves of the OE pulley with the new nut. I also had to get a larger longer bolt and nut for the adjustment arm.
On the wiring I had to take the tape off the harness along the wheel well so that the large white charging wire could move about and bolt up. I had to bolt it up before mounting the alternator.
There is a link above from Salteen post #21 to an alt on ebay. It is a 65 amp (it doesn't say on the ad) and if i had to do it over I would go with it as there would be nothing to change out but the alternator. There is another one on Ebay that looks rebuilt & painted at home. It also looks like a direct bolt up no wiring.

[Gary Lilley]

This is right, but it is also wrong. The blue wire is dead. My Truck is a 1990 with a blue wire and a white wires for the field and the large white wire going to the battery (the charging wire), when I tried this on my blue wire nothing happened, but the other field wire, the white one is hot all the time, (key on,key off, 12 volts) I did this only wrapping the blue wire with tape (deleting it) and using the white wire and it works great. Now my truck is a 1990 dodge ram50 with 2.4 fuel injection. The alternator and voltage regulator came off a '80 dodge slant six D-150. A new alternator was gonna cost me $120. Thanks for the tip!!

[Gary Lilley]

I did have to grind the corner off the bottom alternator bolt hole in the block, the factory alternator has a big space where regular dodge alternators just have 1/2 inch clearance, I cut a hole in my oil filter and had to replace it but I radiused the casting and any dodge alternator will work fine, had to add a few washers to take up the space but the belt lines up perfect and I used the old belt, didn't switch any pullys, used the one on the alternator off the '80 dodge truck.