What soze alternator fuel injection system

[flamesoldier]

i have a 340 cuda and converted to the FAST EFI system which has ECU and electric fuel pump, no radio, no air conditioning, no heater. Will the stock 60 amp alternator work fine or will i jeed larger amperage alternator?

 

[MoparCarGuy]

You should consider a 100-Amp alternator. Powermaster makes factory-appearing alternators that should work.
Mopar Connection Magazine did an article on upgrading the alternator.
Note that the factory wiring is not rated for 100-Amps. The below is a Powermaster chart that lists accessories and their typical amp-draw. You can see how adding a hi-output ignition, EFI ECM, and an electric fuel pump puts considerable more load on the electrical system.

You will need to also consider upgrading your main power feed wire from the alternator to the starter relay post. This requires a decision on upgrading the path through the factory ammeter, foregoing the ammeter, or bypassing it altogether. The bypass is a popular option.
A wired bypass in the engine bay (no path through the firewall bulkhead connector) will need a properly-sized fusible link matched to the gauge of wire you select.
Typically, a 6-American Wire Gauge (AWG) primary feed bypass wire and a 10-AWG fusible link will do the job.

These modifications benefit from some foundational electrical knowledge as, if done incorrectly, can result in an electrical fire. Do your research and propose your plan here so we can provide some assurance your plan is going to safely work.

 

[flamesoldier]

Thank you that’s a lot of fantastic info. My car is mostly original so I don’t wanna hack it all up i love the original look and functionality of the gauges which were restored and working great with that being said the demand chart put me with the 60 amp alternator. 45 amps is what i have based on chart. Electric fuel pump 7-15, headlights 10-20, data recorder for efi 2-10. That outs me at 45

 

[Katfish]

I installed FiTech EFI and electric pump, 60A was plenty. You can convert many of the bulbs to LED which will significantly lower the draw.

 

[72RoadRunnerGTX]

Keep in mind that described “engine bay by-pass”, performed as most folks promoting it suggest, exposes all the factory unfused wiring to more than double the current potential on the event of a short thanks to Ohm’s law as applied to parallel circuits. Connect the added loads on the alternator side of the ammeter to not impact the original wiring, nothing added directly to the battery with this as original charging system. By-pass the bulkhead charge path connectors, check the ammeter connections and leave it be.

 

[Chryco Psycho]

I would stay away from Powermaster tho , I have seen them last less than a week

 

[flamesoldier]

Im just going to stick with the entire factory setup of 60 amp alternator and how system was designed

 

[72RoadRunnerGTX]

To be clear, an all-stock 60amp charging system from this time would have a “Fleet By-pass” from the factory. A bulkhead by-pass, no charge path Packard’s at the bulkhead connector. I’m a “as designed” proponent but the bulkhead charge path Packard’s are, and have always been, the weakest link in this system, they have been failing since these cars were new.

 

[Challenger RTA]

Things That I know are true. When the tools limit of function is exceeded it breaks! When your hand changes tools it takes time. So I use a hammer all the time!
That being said: Ohm's law: When one of the three are exceeded. Damage from heat can be catastrophic. It's usually The resistance that is exceeded do to under designed or corroded connections or wires.
The thing to do is to remove the problem or bypass it. There are different was to do it. 1 remove high current loads by using relay circuits. Such as headlights and or LED headlight as Katfish said. That could be a problem mixing the wrong bulb with the wrong reflector. Not getting the right lighting output. Katfish may share his findings. 2 Clean or replace the connections. Bulkhead, grounds and alternator mounting bolt. 3 If there is a concern about esthetics keeping the original look. Concealed under or to leave accessible to remove for show. By running the bypass along the engine harness and connecting to the starter or the relay. The latter would be easier to remove. There would also have to be a feed through the firewall to the load side of the amp gauge. Via washer foot pump gourmet. While having Anderson connectors that can be concealed under the dash when removed. That being said the original alternator wire would be undone at the alternator while in this configuration. 4 the battery feed side can can be feed that way too. Connect to the battery side fuse box or battery side of amp gauge. Then disconnecting the fusible like while in the by pass mode. Be sure to have fusible link on the battery feed bypass.
Like I said it could be all removed with minimal effort. and lest evasive. And it would be more aesthetically pleasing. Not burnt to a crisp.

 

[MoparCarGuy]

Current-splitting is Kirchoff's Law and @72RoadRunnerGTX is making everyone aware of the dangers of incorrectly modifying your charging/electrical system.

 

[Challenger RTA]

Current-splitting is Kirchoff's Law and @72RoadRunnerGTX is making everyone aware of the dangers of incorrectly modifying your charging/electrical system.

Yes I agree with that. In short I was saying. When connecting the bypass. Disconnect the alt wire and battery fusible link from the starter relay. They will still have live ends. Cover with heat shrink and it can be removed when needed or wanted. The relay circuit will remove about 17 amps minimal from the load on low beams. Being that the relay circuit is connected the alt load.