Regulator conversion to 1970 late model charging system question

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fxrtharley

fxrtharley

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Hello, I have read posts about changing old regulator/alternator to post 1969 system. A couple questions, one: It shows i the diagrams to splice the blue wire going into the old regulator but my regulator has two blue wires. One blue and one with white tracer. What is the other wire and do I splice both wires into the new regulator? Two: Can I upgrade my old alternator to use the two fields or do I need to purchase a new alternator?

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I don't know the digram you are referring to but the two blue wires if they are together now should stay together.

As for your alternator.

If it is a square back then technically yes you can get the appropriate brush insulators to turn it back into an isolated field.

Now for my 2 cents..


Let's say down the road you need an alternator and you go to the parts store and tell them you have a 69 Dart.

They give you a square back and your thinking it's all good.

You put it in and now you are over charging, like 18v or worse off your blue wire melts and catches your car on fire.


This sounds extreme but the reality is it could and has happened right here in FABO.

See round back cores are few and far between so the rebuilders modify a square back to work with a single field wire regulator system. That means 1 field terminal is grounded and the other is not.

The grounded terminal is typically cut off by the rebuilders BUT most of the time there is enough that you can hook a terminal on it. And again has happened to folks right here on FABO.

if you hook the blue wire from the ballast/ignition run cir to the ungrounded terminal on the alternator you will get over charging

If you happen to hook the blue wire to the grounded terminal then you will have melted wires from the alternator to the ballast to the ignition switch, to the splice and to the fusable link to the battery.

So the point....

There is nothing wrong with the single field wire alternators or regulators.

They have works fine for 60 years.

You really have nothing to gain but headaches by making the change.

People will argue that the square back alternators have better low rpm performance, sure, but the pulley diameter will fix that.

I have video of a round back with a 2.5dia pulley and a square back with a 2.75 to 3.0 dia pulley and the round back was rock steady at idle but the square back was fluctuating.

Good luck to you
 
Hah! Looking in my Crystal Ball and mumbling a few phrases I'd say we're looking at a '69.

I agree 100% with Dana. If there is nothing wrong, leave it alone.

An alternator only supplies the power that is needed.
It takes about 5 amps to run a '69. About half flow to the ignition and the other half to power the field.

After starting, the alternator also has to recharge the battery. That can be 10 or 15 amps very briefly and then less.
Look at the ammeter and observe if it swings from slight discharge during starting to charging once its running.
When its done recharging, the needle goes to zero.
 
Thanks for the replies. I was just looking into have consistent voltage to lights at idle since they dim a lot. Also it has electronic ignition and forums I read say the EI’s want the upgraded system as well as the old regulators are less reliable.
I have a 68 Barracuda AC (removed) now 340 Barracuda
 
You can get an electronic version of the single wire regulator. That's what I have.

Works great.

If you have issues at idle measure your alt pulley dia
 
Back in the day Direct Connection did recomend the solid state voltage regulator for the mopar ECU.
It was a blue painted version of the solid state regulator made as replacements for Studebakers.

In any event, the VR in your photo doesn't look like a points type regulator. They generally have metal housings and two resistors underneath.
You may already have a solid state regulator.

Dimming lights at a stop on an A-body is not unusual.
A few possibilities to look into:
Changed alternator. An A/C equiped car would have had an upgraded alternator over a plain slant 6 car. But when a replacement was bought - its a crapshoot.
Change in the pulley ratio. Replacements and changes can sometimes end up with a slower turning alternator.
Replacement alternator has a high field current. Sometimes higher output alternators require higher rpm before producing and steal more energy from the system.
Slipping belt. Don't shrug it off. I just had that with my Jeep wagoneer with '94 amp' 12SI alternator. At idle the v-belts (yes two) would slip just enough when the alternator had a high load at idle (lights and brake lights) to force the battery to take over. Simple fix.

You should know that most replacement headlamps draw more current than the originals (6012 bulbs).
A great improvement in lighting can be had by installing a relay system power the lamps directly off the alternator. This also reduces the load on the power connections at the bulkhead and headlight switch connector. It may or may not resolve the dimmer lights at idle.

Two blue wires together at the regulator is unusual for a '68. Is one wire powering the ECU ?

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R6 is the alteRnator output wire.
J2 is Ignition Run, blue wire with white striped.
J2A is the branch to the regulator and power the alternator field.
 
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The. Lue wires go into a harness so not sure where they go.
I will check my regulator which could be solid state. I will also visit an alternator rebuilder who can help me with amperage and pulley size
Thanks for your help
 
Headlite dimming at idle is normal, - 3500 rpm at 70 mph is normal.
New cars with improved electronics and overdrives have totally screwed up people's expectations.
I'm not concerned about my long range vision while at a stop light.
Can't imagine some folk with a Model A . lol
jmo
 
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