Alternator Wiring Question

[pstu]

Hi all, happy new owner of a 1965 Barracuda with a 1971 340. Previous owner made some interesting choices in the ignition wiring. I'll try to keep this short. As seen in the diagram, the alternator has a wire going straight to the positive battery terminal. From the wiring diagrams I've seen, this is incorrect, it should have two outputs, one to the ballast and one to the voltage regulator. I've also found that IGN1 and IGN2 are connected together from the ballast (B and A) and connected to the Ignition input to the Mallory Hyfire IV. I've been told I need a "one wire exciter" but I'm not clear on how I would wire this. Any suggestions or advice, please!

 

[Mattax]

I've been told I need a "one wire exciter" but I'm not clear on how I would wire this.

That's GM talk.

A 10SI or 12SI and later GM AC generators (alternators) have an internal voltage regulator that needs an exciter connection for low rpm and to get working. They also need a reference wire to know what the system voltage is. However they can also be wired internally with both of those inputs. Hence the 'one wire' alternators which are fine for tractors and such, and somewhat popular with hot rodders.

I've also found that IGN1 and IGN2 are connected together from the ballast (B and A) and connected to the Ignition input to the Mallory Hyfire IV.

With a capacitive discharge ignition, that will work. It just signals the Hyfire to turn on.

As seen in the diagram, the alternator has a wire going straight to the positive battery terminal. From the wiring diagrams I've seen, this is incorrect, it should have two outputs, one to the ballast and one to the voltage regulator.

Factory system from '62 to '74 ran the alternator output to a central distribution point were it connected with the main circuits using a welded splice. On a standard system it also jointed with the battery output/charge circuit at that splice.

In '65 they began installing a fusible link on the battery output to help protect the main circuits if any of the 12 gage wires grounded.

 

[Mattax]

None of my factory gauges work 65 dart gt

Like the title says, my alternator, temp, and gas gauge do not work. Speedometer doesn’t work either which is strange because the cable is attached to the back of the Speedo and to the transmission. The lights for the guages all work. The turn signals indicators work, wipers work, but those 3...

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www.forabodiesonly.com

 

[273]

Are you actually having a problem with his wiring or just don't like the job he did or want to make it stock etc.. ?

 

[pstu]

Are you actually having a problem with his wiring or just don't like the job he did or want to make it stock etc.. ?

All 3.
I don't believe my alternator is currently charging my battery. I should add the current alternator is a ford alternator, I'd like to switch to a chrysler alternator, but not sure where I would wire the FLD1 and FLD2 connectors to.

 

[273]

All 3.
I don't believe my alternator is currently charging my battery. I should add the current alternator is a ford alternator, I'd like to switch to a chrysler alternator, but not sure where I would wire the FLD1 and FLD2 connectors to.

I got to do similar to mine, I'm gonna start from scratch and design my own under the hood wiring, I don't know how good you are with wiring, I'm ok, with a little thought and research I can get it done, there's only a few circuits to deal with, you probably want some version of modified stock, learn all the stock under the hood circuits first, then figure out how to get back to stock then figure in your upgrades then draw it all out then go about rewiring it. You should have it decently mapped out in your head before starting.

 

[RustyRatRod]

Go to Mymopar.com and see if they have a download of the 65 plymouth service manual. They're free. That will have the correct wiring diagram for your car.

 

[273]

This guy got a bunch of video's on basic car circuits

 

[pstu]

Thanks. I've been going over the wiring diagrams many times. I guess my ultimate question is, if I add a Chrysler alternator, where do I wire the outputs to, considering IGN1 and IGN2 are spliced together. Do I still need two outputs? Do I need a voltage regulator?

 

[273]

Here's some images I found might help, someone better than me would need to talk you through it.

I'm good at getting places bad at giving directions

Modified probably similar to yours

Stock ones

armature bypass

 

[Mattax]

All 3.
I don't believe my alternator is currently charging my battery. I should add the current alternator is a ford alternator, I'd like to switch to a chrysler alternator, but not sure where I would wire the FLD1 and FLD2 connectors to.

Interesting choice of a Ford alternator. Don't see or read about using Motorolas that often. Put a photo we can get a better sense of what you're dealing with. Chrysler actually used Motorolas a very little bit - I saw a reference in the Hamtramck Historical Library - maybe for postal delivery trucks one year. in the late 60s. I'm sure that's not what you ahve.

If you actually want to see whether the battery is charging, then you need to wire the system like Chrysler did with a seperate leg for the battery charge/feed. The ammeter in this leg of the circuit will show if electrons are flowing into or out of the battery.

How this works^^^
Imagine the engine is off. Turn on the headlights. The electrons flowing through the ammeter create a small magnetic field causing the needle to swing toward discharge. Same if the engine is running and the alternator is not working.
If the alternator is working, after start up, the needle swings toward charge until the battery is full.

If you just want to know if the system is running on the alternator vs. battery power, then a voltmeter will do the trick. It will show whether the system is seeing 14+ volts or 12.5 ish volts at whatever location you tied it in.
I would tied it into the run or the switched accessory circuit so it is only on when the key in run or accessory.

 

[Mattax]

I'd like to switch to a chrysler alternator, but not sure where I would wire the FLD1 and FLD2 connectors to.

If the Mallory is anything like the MSD, it doesn't care if there is or isn't a ballast resistor. You could install if you wanted. it will run the same.
The Hyfire gets its working power from the connection to the battery positive. It builds a charge and sends through the coil.
Now that connection might be best to leave on or near the battery if the Hyfire is sensitive to electrical noise. It probably doesn't care but I don't know that.

Now to field connections. Take a look at "How to Identify Chysler Alternators".
If you are using a grounded field regulator (as would have been in '65) then connect power from the run circuit to the regulator. Then there is one field wire to the field terminal on the alternator. The second field terminal is grounded to the housing. Simple.

If you are using a regulator for alternators with two insulated field terminals, one terminal of the regulator gets connected to the ignition run wire, and one field terminal gets connected to the ignition run. The other field terminal gets connected to the voltage regulator.

 

[pstu]

 

[pstu]

Photo below. I believe the Ford alternator was added by the previous owner, unknown why.
If I connect the two fields (one passing through the voltage regulator, see my sketch above), is it safe to splice them into the brown and blue wires coming from the bulkhead, like what 273 posted above?

 

[Mattax]

View attachment 1716213312

Well that's a mess and will cause trouble at some point. Take a look at some of the threads on how the wires are typically bundled and supported, as well ones on crimping and splicing. '65 has a unique bulkhead connector - similar to '63 so any comments, claims and generalizations do not apply. However we've seen those damaged too - anyhting can be abuse. My point was it will be useful to look at the '65 specific bulkhead connector info if you need to work with it.

Looks like an OEM ballast resistor on the right inner fender. I'd ohm it and see if its good. For an OEM look you can find a busted one and hang it for looks in the right spot or run a wire inside (its busted anyway) connecting the terminals. The Hyfire is hard to hide! I see four wires on the battery positive? Can't see the alternator enough to comment further. Maybe it has the right brackets for a mopar alternator, maybe not. A Denso alternator is not a terrible option either.