6.4 hemi charging system?

[MOPARCODY]

good evening fabo. im doing some research on alternators. it looks like ill have to use a 1 wire alternator with my holley terminator engine management. does anyone have any experience with converting the oem style alternator to 1 wire? im not even sure that its possible. i just really dont want to spend the $400 on the bouchillon unit.

tia

 

[AUSA66]

I just bought 1 of these $120 USD wired it up all fitted i haven't run the engine yet looks like a standard old orange reg has a voltage adjuster on the rear

Have one to sell?
Sell it yourself

ERCKFRM-071 = ERCKFRM/Driver/Plug Combo Chrysler Dodge Ram Jeep VW +​

 

[67Dart273]

I do not care, generally speaking, for "one wire" alternators.

If you race, they complicate making the system safe with a disconnect

The charge wire needs to be GREATLY oversized, because it is also the sense wire. This means a much more dangerous large wire to worry about in the case of a short

BUT I do know that lots of guys use them. DO NOT DO NOT connect ANY alternator larger than (let's say) about 50A to the old original harness. Make CERTAIN the bulkhead connector is repaired/ in good shape, BYPASS the ammeter, and then run a LARGE fuse/ breaker protected charge wire direct from the alternator to the battery

You MUST research to discover recommended wire size. Obviously, if the battery is trunk mounted, this means that wire needs to be even larger because of length

 

[67Dart273]

There is no reason, really to "convert" the old unit. THE MAIN REASON any charging system other than "one wire" give you voltage trouble is

1...The alternator AND regulator MUST BE grounded to battery negative. In other words NO voltage drop

2...In the same vein, the battery voltage supplying the VR MUST not have voltage drop. This is the path through the ignition switch. You probably need to add a relay to key underhood loads, including the VR

BUT IF YOU DO, AGAIN, research a large enough charge wire AND FUSE / BREAKER protect it.

 

[67Dart273]

This is one opinion on 1 wire --wire sizing. Not sure I agree. It shows no6 clear up to 100A. I think I'd be tempted to step up to 4 ga at about 80A

The thing you must keep in mind with a "one wire" is that the more load that is on the alternator--pumps, fans, and charging the battery, the CURRENT flowing through the CHARGE wire causes VOLTAGE DROP. The only reference the "1 wire" has is right at the alternator. So if that reference keeps the alternator at 14V nominal AT THE ALTERNATOR, and the charge wire is a bit too small--or too long--by the time you get to the other end, you may be down to 13 or less under heavy load

 

[67Dart273]

This site talks about automotive (NOT house wiring) ampacity for TWO PER CENT VOLTAGE DROP. If you are going to talk about wire capacity, you MUST consider and specify how much drop you are willing to accept

Automotive Wire Amperage Capacity Chart - Jasco Automotive Ltd

AUTOMOTIVE Wire Amperage Capacity Chart Recommended Length and Amperage for Automotive Wire while maintaining a 2% or less voltage drop at 12 volts Automotive Wire Size 5 Amps 10 Amps 15 Amps 20 Amps 25 Amps 30 Amps 20 Gauge Wire (AWG) 4.5 ft 2.2 ft 1.6 ft . 18 Gauge Wire (AWG) 7.3 ft […]

jascoautomotive.com

2% of 14V is about .3V (.28)

You also must know the LENGTH and you must know if that length figure is taking in the GROUND SIDE, such as in a wood boat, where there is no frame or body ground.

This chart here, EG, shows that no 8 ga at 12.4ft wire length, and at maximum of 2% drop is ONLY GOOD for 30A

Automotive Wire Amperage Capacity Chart

Recommended Length and Amperage for Automotive Wire while maintaining a 2% or less voltage drop at 12 volts Automotive Wire Size 5 Amps 10 Amps 15 Amps 20 Amps 25 Amps 30 Amps 20 Gauge Wire (AWG) 4.5 ft 2.2 ft 1.6 ft . 18 Gauge Wire (AWG) 7.3 ft 3.7 ft 2.4 ft 1.8 ft 16 Gauge Wire (AWG)...

wiringproducts.com

 

[AUSA66]

The standard Hemi 6.4 Alternator seems to be 220 Amps I used 50mm2 from the alternator then 70 MM2 to the rear battery protected by a 240 Amp Fuse at the Starter motor to alternator or step down point also aids in faster starter motor speed due to less volt drop also the cable is double insulated to give better wear resistance being in the welding game helps .
If the alternator cable gets damaged or Alternator fries either the fuse blows or the diodes get blown apart.

 

[DionR]

Found this: https://www.forbbodiesonly.com/mopa...users…no-alternator-wiring-in-harness.254416/

Looks like the alternator is PWM and can be run with the Terminator by setting up a PWM output. One trick is that the Terminator appears to ground the circuit while the alternator expect positive voltage, so you have to use a relay that can be PWM’ed.

There is a response in there too where a guy used an external regulator on a 6.1 alternator, but my guess is the 6.1 didn’t use a PWM alternator.