Another Alternator Question

[m99roadster]

Not wanting to hijack jerry6's thread I thought I'd ask here. I'm having a 340 put in my 68 Dart, the shop it's at has already purchased a Powermaster 140 amp alternator am I looking for trouble? What modifications should I have them do or should I downsize the alternator?

 

[RedFish]

Any alternator will supply only what is required or called for in the system.
Circuit protection should step up to the task if there should be a short circuit.
The most effective way to do that is with more than one power take off at the "batt" stud on the alternator, followed by fuses and relays for the various circuits.

 

[Beatnik]

Maybe a better question is do you need that alternator? Are planning on running elec fuel pump, elec fans, big sound system etc? If not why not just run something closer to a stock type replacement? If so....then substantial wiring upgrades all around are logical anyway.

 

[67Dart273]

I would NO WAY run that big wheel on factory wiring. Read the MAD article and "do" the bypass.

The factory knew full well that these bulkhead connectors are weak----they bypassed 'em when supplying 60 or 65A optional ammeters. These are known variously as "fleet" or "taxi" wiring.

The MAD article, a good read whether or not you bypass the ammeter:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Some stuff on fleet wiring

http://www.forabodiesonly.com/mopar/showthread.php?p=1969960437

Here's an EXCELLENT thread. Read all three pages. This details how easy it is to pull the ammeter apart and mount a voltmeter in it's place. This covers several styles of instrument clusters

http://www.forabodiesonly.com/mopar/showthread.php?t=119480

 

[goldduster318]

With a 140a alternator, you're looking at about a 6 ga wire from the alternator to the battery (or starter relay).

I have a Delco 12si on my car (only a 78a version), and at least before the electric fan install (haven't driven it at night yet) it was more than enough. I can't imagine that you'd need more than 105a for anything you'd be running on these cars unless you have a competition stereo. I have a 2012 Chevrolet Cruze with power windows/locks, electric fuel pump, fuel injection, vacuum pump, electric fan, a/c, 250W stereo, heated seats, etc...and it only has a 120a alternator. My '04 Colorado and many older FI cars only have 100-105a alternators.