The alternator on my dart quit charging last night, prior to that it was making not so good rumbling noises. So I need to replace that. My question is how big (amperage) of an alternator can i get?

Car is 72 dart swinger, but I have added some things that will put more load on the battery:
Nitrous system with bottle heater
Electronic fuel injection
Electric fuel pump
MSD 6al ignition
Electric Fan
Amplifier for stereo

Can my wiring system handle a higher amp alternator if so what would be recommended?

I would like to get a single wire with a the regulator built in. Is there anything I should know before doing this or is it fairly straight forward?

Thanks.

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Ryan Covalt
62 Plymouth Valiant Race Car 2170# 11.008 @ 117.65 MPH 1/4 Mile Best
72' Dart Swinger Street Car, 4 spd, 3330# 14.061 @96.58 1/4 mile Best

You cannot just toss a high-amp alternator into a car with stock wiring; you will soon do extensive and costly damage to your electrical system (main charge wire, bulkhead disconnect, ammeter...if you're lucky the damage will be confined there. If you're not as lucky you'll have a fire).

There are several ways of upgrading the charging circuit. I don't like the hack-azz "solutions" offered at the (chevy-head) Mad Electric site, but their basic premise is correct; you have to either seriously beef up the ammeter or bypass it or replace it by a voltmeter if you're to safely run a high-amp alternator. The quick "get it on the road" method is to connect the alternator's B+ output terminal to the battery positive terminal with two 10ga wires run along the underside of the lip of the radiator support panel. Ammeter no longer registers charging current, but charging circuit is adequate.

I prefer to have a working ammeter, so I much prefer the clean and technically correct ideas and components from R/T Engineering. They can rework stock ammeters to handle up to 70 amps efficiently, and they can convert stock ammeters into voltmeters (complete with a new gauge face that looks like factory equipment). They also sell a really good electronic instrument cluster voltage limiter. Their website's got a bunch of really good info on it, but you have to mouse around awhile to find it; the organisation isn't completely obvious. For example, I know there's a pic of one of their voltmeter conversions somewhere on the site, but I can't find it at the moment! Be sure to see this page. They actually have intelligent people who actually answer the phone, so if you get fed up trying to find what you want on the site, call them.

I used their electronic limiter on my '71 Dart, and now since I need to go in the dash of my '73 to replace a dead temp gauge, I figured I'd beef up the ammeter in prep for swapping on a late-model alternator. Should've called RTE before I bought a good used ammeter off eBay intending to send it into them for upgrade then swap it in, for two reasons:

1. The eBay seller (finally) sent me the wrong ammeter. It's a '76-only A-body ammeter, which is an external-shunt type unit. I could swap it into my '73, but I'd have to create an external shunt on the engine side of the firewall, of the correct capacity to make the ammeter read correctly.

2. RTE informed me when I did call them that they have upgraded A-body ammeters for sale on the shelf, either with good used/cleaned-up faces or with newly-restored/reprinted faces. $75 or $99, respectively.

Another interesting option is this retrofitment of a current-production aftermarket voltmeter with the original ammeter's face, see thead on FABO (start at post #51).

There are other gauge specialists who can likely offer good solutions, I'm just not familiar with them. www.gaugeguys.com is referenced and recommended in the linked thread.

Without modifying the car's circuitry, you're safe if you keep it below 50 amps; higher than that and the existing wiring will not tolerate it. Do not get a "remanufactured" alternator from a parts store (or from Summit); they're junk. You can get a brand-new Chrysler 46-amp alternator from Old Car Parts Northwest, 206-300-1083. Guy's name is Ray; tell him Dan Stern sent you.

You mention a 1-wire alternator. Why? What are you trying/hoping to achieve? The reason why 1-wire alternators exist is to solve voltage regulator availability or hookup problems, which Mopars don't have. The issues that need attention on most older Mopars are related to the charging circuit itself, not the alternator control circuit--see above.

To upgrade to a more modern (smaller, lighter, more efficient, higher capacity, greater output at idle) alternator, an easy and very satisfactory pick is from an '88-'91 Dodge Dakota, D-series truck, or B-series van with a 3.9 V6, 5.2 V8, or 5.9 V8; or an '88-'89 M-body (Diplomat, Gran Fury, New Yorker Fifth Avenue, or Canadian Caravelle). Does not matter if it's the Chrysler, Bosch, or Nippondenso unit; all three are physically and electrically interchangeable. The Nippondenso is the best design, also the smallest and lightest. Any of these three is much more efficient and has much better low-RPM output than any of the older Chrysler-designed alternators. They come in two ratings: 40/90A and 50/120A. The first figure is max output at engine idle speed; the second is max output regardless of speed. The 40/90 is usually plenty, but you've got a lengthy electrical "shopping list" (high demand) so you might want to go 50/120. Case size is the same for both ratings. I You will need to do some bracket adaptation, which consists of shaving 1/8" off the bottom pivot bracket to accommodate the newer alternator.

Whatever alternator you wind up with, run a ground wire, 14-gauge, from the "GRD" hole on the back of the alternator to the voltage regulator base and from there to the battery negative terminal.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dan, Thanks for taking the time to answer my questions your post was very helpful. I think I am going to go ahead and order a new nippondenso 50/120 alternator like you mentioned. I will also bypass the ammeter temporarily until I choose a better solution. I am hoping to upgrade the instrument cluster for racing and better functionality (not originality) so if I can bypass the ammeter for now I can get the dash figured out later on. Thanks again.

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Ryan Covalt
62 Plymouth Valiant Race Car 2170# 11.008 @ 117.65 MPH 1/4 Mile Best
72' Dart Swinger Street Car, 4 spd, 3330# 14.061 @96.58 1/4 mile Best

Be sure to bolt & nut with lock washer the two eye ends of main supply conductors that were removed from Amp Gage’s terminals, than tape them up real well using 3M’s #33 electrical tape; "the good stuff". It is a bit more expensive, but will keep well and still be serviceable for years

Cheap electrical tape will not stay stuck, will unravel, and gets brittle when cold. The last thing you want to have happen is that connection coming loose, arcing, or to wear through tape and coming in contact to ground.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Thanks for the advice. I definitely don't want to start a fire because I used cheap junk tape. I'm not sure what I have in the shop, but I will get some new 3m. Hopefully will get the Dart back on the road soon!

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Ryan Covalt
62 Plymouth Valiant Race Car 2170# 11.008 @ 117.65 MPH 1/4 Mile Best
72' Dart Swinger Street Car, 4 spd, 3330# 14.061 @96.58 1/4 mile Best

My preference is to run the alt output straight to the battery (or the starter relay post.) A voltmeter gives plenty of useful info about charging system operation & does away with the ammeter loop.

Whatever you run be sure to have the system protected by the correctly sized fusible link. If your alt B+ lead is 10 ga., use a 14 ga. link. If it's 8 ga then go to 12 ga. link. (2 wire sizes or 4 numbers down)

Most "1 wire" alts tend to charge poorly at low rpm (& need high rpm before they start charging at all) The mopar system is the most simple & reliable setup out there - period.

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63 Valiant Wagon
225 - 4 bbl

I would be very interested in running the alternator straight to the battery then adding a voltmeter. I ordered the new alternator for a Dakota (50/120) like Dan recommended, it should be here soon. Is there a downside to running the alternator straight to the battery? other than losing the ammeter?

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Ryan Covalt
62 Plymouth Valiant Race Car 2170# 11.008 @ 117.65 MPH 1/4 Mile Best
72' Dart Swinger Street Car, 4 spd, 3330# 14.061 @96.58 1/4 mile Best

Forgive my electrical ignorance. But if the new Alternator is wired directly to the battery, what happens to the existing main feed wire from the old alternator? Does that wire need to go back to the battery then? I'm sure I'll be helping Ryan so thanks up front!

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Nothing. You can hook it up if you like, or leave it disconnected.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan ,

I'll talk to Ryan (his car) but it sounds like we can just shrink wrap/tape the old wire up and leave it there in case he would ever need it for anything. Much appreciated!

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Dan is there any reason to run 2- #10's across? Can we just run a single wire and single fusible link? What sizes would you recommend for that? Thanks again,

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Yup: bigger than 10ga gets unwieldy and difficult to attach cleanly to the alternator B+ terminal.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

So 2 number 10's it shall be. I'm assuming that these 2 wires can't run through a single fusible link at the end? That each one needs one F/L.

Thanks,

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Yeah, put a fuselink on each.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks for the help Dan. I ordered the nippondenso alternator you mentioned and they sent a "similar" one that came from taiwan and wasn't even close. I am going to send it back and try to get the Denso unit again. Hopefully I will be able to get started on the re-wiring soon. Thanks again.

_________________
Ryan Covalt
62 Plymouth Valiant Race Car 2170# 11.008 @ 117.65 MPH 1/4 Mile Best
72' Dart Swinger Street Car, 4 spd, 3330# 14.061 @96.58 1/4 mile Best