Alternator thoughts?

[DonCarter66]

Hey all, I brought this up in the Intro forum, but this is a better place. I want to upgrade the charging system. I have decided on using aftermarket gauges and much more robust wiring, headlight relays, etc. when I tear down the car next year to bare metal. I want to go up to either a 75A or 100A alternator. My question is regarding whether anyone here has switched from an externally-regulated alternator to an internally regulated one. Most of what I see as direct replacement units are one-wire, square-backed alternators offered as either internal or external as far as regulators. Thoughts?

Car is a 1968 Satellite convertible with an actual 6BBL 440 from 1971. AM radio right now, will add a stereo and decent but not over the top sound system, and possibly an aftermarket a/c system in the future. I will be going with electric fans for sure.

Thanks,
Don

 

[SomeCarGuy]

See what a local alt shop can build for you. My recipe is best they can do, new YO harness, 70 up regulator, and a shunt to the battery. That always works well for me.

 

[DonCarter66]

Update.
Pulled the pre-1970 regulator harness (the whoppingly complicated 2 wires) today, found that the green wire female connector on the alternator side stayed on the alternator. No wonder I was getting no charge. Started poking around further around the bulkhead connector, and found the 8-10 gauge wire going from the alt stud on the starter relay to the bulkhead connector was starting to distort the bulkhead connector, but had not melted it yet. I fabbed an 8 gauge cable, tinning, crimping, and soldering gold-plated audio HD ring connectors. Double-shrink wrapped all joins. I used 11 gauge fusible link. This I routed along the inner fender on the passenger side, then along the firewall to the bulkhead connectors. Attached this directly to the batt stud on the starter relay. 12.56V at the battery with car off. 14.56V while running at 1500 rpm. Still going to upgrade to a 100A square-backed, externally-regulated alt. Need to make a new harness from alt to bulhead connector that routes along the new cable instead of running over the intake manifold next to the valve cover.

 

[Jim S.]

Yeah get that electrical stuff "sured" up. There are a lot of older threads (and info) on here about the bulkhead connections. Also be aware that the amp gauge itself can be the source of excessive current draw (high resistance) on its outside connections or internally. You probably already know that though, sounds like you are on the right track.....

 

[69hemibeep]

Sounds like your on track. The police cars always had good alternators my brother has one on his challenger with all the bells and whistles and no troubles.

 

[DonCarter66]

Yeah, going to replace the pre-1972 setup with the 100A unit I found at Summit, flat regulator, and build a longer, beefier wiring harness to get the existing one off of the motor. And yes, I am thinking that a Chebby guy did the crap paint and body... black engine bay indeed! Looks like crap.

 

[Big John]

I'm going to play the devil's advocate.

Do you really need a 100 amp alternator?

Our cars really don't have all the electrical draw that the newer cars do. The new A/C system really isn't going to draw that much (if any) more then the stock heater. Electric fans? Well.. yea, a little more draw, but 100 amps?

Seriously, all you need is enough amperage to keep the battery charged. Anything above that is a waste of money and horsepower.

Making the wiring right is huge. Shunt past the bulkhead connector and maybe bypassing the ammeter is next. I like to upgrade to an electronic regulator but I don't change to the 70 and up dual field alternator. The dual field is NOT an upgrade.

Again, just offering an option.

 

[george68hemirr]

I'm going to play the devil's advocate.

Do you really need a 100 amp alternator?

Our cars really don't have all the electrical draw that the newer cars do. The new A/C system really isn't going to draw that much (if any) more then the stock heater. Electric fans? Well.. yea, a little more draw, but 100 amps?

Seriously, all you need is enough amperage to keep the battery charged. Anything above that is a waste of money and horsepower.

Making the wiring right is huge. Shunt past the bulkhead connector and maybe bypassing the ammeter is next. I like to upgrade to an electronic regulator but I don't change to the 70 and up dual field alternator. The dual field is NOT an upgrade.

Again, just offering an option.

I AGREE

:yeathat:

 

[DonCarter66]

Stereo system... AM just does not cut it for my daily driver. We have exactly one station with music, and I am not a huge fan of Mexican Polka/Mariachi. I make frequent 2-3 hour trips (each way) to the VA Medical Center and the beach. I have to calculate up the total draw regarding what is going into it. There is also the 75A version, just depends on the total draw I need with a bit of headroom.

Loving it, you guys are making me think.

 

[6t9runner440]

A few years ago I got a 70 and up conversion kit from US Car Tool...came with the electronic regulator, alternator, and wiring harness...best thing I did to my car...never had any trouble...lights don't dim at idle etc...wonder if they're still available...John's right...100 amp is a lot

 

[DonCarter66]

As far as the ammeter, that fat 8 ga wire near the heater hoses goes from the output stud on the alt to the battery stud on the relay. I have noticed that all of the dash lights are much brighter. From everything I am reading on the electrical diagrams I need the 2 field outputs to use the electronic regulator, so I would need to go to the later square-backed 2-wire alternator no matter what. I consider it an upgrade not to have to solder and press individual rectifiers :brickwall:

 

[6t9runner440]

As far as the ammeter, that fat 8 ga wire near the heater hoses goes from the output stud on the alt to the battery stud on the relay. I have noticed that all of the dash lights are much brighter. From everything I am reading on the electrical diagrams I need the 2 field outputs to use the electronic regulator, so I would need to go to the later square-backed 2-wire alternator no matter what. I consider it an upgrade not to have to solder and press individual rectifiers :brickwall:

Yep...the alternator they sent me was two field...65 amp If I recall correctly

 

[Big John]

As far as the ammeter, that fat 8 ga wire near the heater hoses goes from the output stud on the alt to the battery stud on the relay. I have noticed that all of the dash lights are much brighter. From everything I am reading on the electrical diagrams I need the 2 field outputs to use the electronic regulator, so I would need to go to the later square-backed 2-wire alternator no matter what. I consider it an upgrade not to have to solder and press individual rectifiers :brickwall:

There's electronic regulators available for the single field alternator. VR706 is the part number for Autozone's version.

The two field connections are kind of misleading. It isn't an output. It's how the alternator is controlled by the regulator... and there isn't another field.

The dual field is really an "isolated field" alternator. It has two connections for the field, one connected directly to 12 volts and the other to the regulator. The earlier style has one external field connection that connects to the regulator and an internal connection to ground.

No difference in performance. Just a difference in the single field alternator using positive voltage and the dual field using negative to control output.

And solder in rectifiers.... Yea... got that correct. That's a pain... but with getting the wiring straightened out and an electronic regulator you'll find that you aren't replacing them near as much.

Good to hear you are thinking!!!! Keep it up!!

 

[DonCarter66]

My bad... I still don't fully understand the operation and terminology as it applies to alternators. I am pretty instinctive as far as understanding goes, still trying as far as the actual engineering side. Y'all are helping me loads already.

 

[DonCarter66]

I cannot seem to find 60 amp one wire externally-regulated alternators other than a few at autozone/advance auto, and I am not finding the output specs on those. I like the prices though, less than $60... *edit: I found it at Advance. Check one off.

How does one adapt the 70-up flat regulator to the one-wire alternator? I have 3 of them from the parts box that came with the car, along with the orange MP control box (I have an MSD distributor that has everything internal, so no ballast resistor or control box).

Regarding the amperage, not set on anything other than what I need to power everything with a bit of room to spare. I am thinking that the final current draw will be no more than a loaded police car of the era. Going to relays for the headlights, stereo system etc...

As far as wiring, for now I am going to get the YO engine harness, but I am a firm believer in overengineering stuff. The factory used stuff that was good enough at the least cost. I can afford to spend extra to use larger wire as I am not building hundreds of thousands of vehicles

 

[6t9runner440]

maybe this will help...check diagram 3

http://www.mymopar.com/charging.htm

 

[DonCarter66]

maybe this will help...check diagram 3

http://www.mymopar.com/charging.htm

Perfect, thanks! Of course that still means getting an alternator with 2 field terminals... or using the shiny Chinese part from Auto Zone that looks like the electro-mechanical regulator except it is riveted closed. Maybe I am just not understanding if this is not what it means.

 

[Jim S.]

You can ground one of the field terminals, doesn't matter which one. Just run a short wire to the alt. case.

 

[DonCarter66]

Hey Jim... From reading that schematic it looks like 2 field terminals are required for the solid state units. I guess my confusion is in how to use a one field terminal alternator with the 1970-up electronic regulator. I have no problem making a wiring harness from a schematic, but this is really confusing me.
So to state my current understanding, I get a 1968 YO harness, a 1970-up 2-wire square-backed alternator, one of the Mopar fully electronic regulators, and slightly modify the 1968 harness? I am feeling particularly dense here. Where is the "drool moronically" emoticon? Sorry to be so dense on this.
Thanks again,
Don

 

[Jim S.]

I put a electronic VR706 reg. inside my old reg. case and grounded one of the alt. field terminals.
Take a look at this old thread....

viewtopic.php?f=6&t=2768&p=31819#p31819