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Voltage Regulator - Best Street Choice?

Oldtimer

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Following initial road tests of my 68 GTX 440, my dash mounted full sweep AutoMeter Volt Gauge is indicating 14.5 Volts (Constant Output),
from what I believe is an aftermarket 'Race Only' regulator, which according to Summit's advertising, is only supposed to generate a maximum
of 13.5 Volts of (Constant Output).

I am thinking this regulator should be swapped out for something a little cooler on my electrical system, and perhaps saving my battery
from being fried.... I am not running any high demand, or outrageous electronics...., so, I should be good to go with a stock regulator.

This is the regulator currently installed:

Voltage Regulator 13-5V.jpg

I am considering, the below repo stock job:

Stock 60-69 Voltage Regulator.jpg

OR would the following, be a better and more stable choice?

Voltage Regulator P4529794.jpgVoltage Regulator Pig Tail.jpg

Here is a comment I read today, posted earlier by a customer on the Summit Racing website, who bought this regulator.
Together with all the kind suggestions of nms9theham, this regulator looks like a good choice, if a replacement is needed
and you are not concerned about having an 'original' charging system - on rides preceding this technology.

Quote: "I looked for product information about the internal electronics but didn't come up with much until I researched some forums.
This is the best voltage regulator to use for street use in your Mopar muscle car, hands down. It uses modern electronics and looks great on the firewall.
I installed it in my pro street '70 cuda with a high output alte
rnator and it works awesome. After starting the engine, at idle it holds 12.8 VDC and once
you go off idle it builds from 13.5 VDC to 14.2 VDC, then stabilizes at 13.8VDC after a while. Perfect for my use."

What do you think?
 
Last edited:
All the others should give you higher voltage than the race only regulator.

To what point in the system is your AutoMeter gauge connected?

What alternator do you have? Does it have 2 smaller wires to field connections on the back, or just 1?

You may have to do some troubleshooting to run down some voltage drop in the system that is causing the regulator to put out higher voltage in an attempt to compensate. YOu will need a regular voltmeter to run this down. Basically you need to check the voltage from the battery- to:
1) the regulator case; should be very near 0; if not, there is a ground issue
2) to the battery+ record this
3) to the voltage feed to the regulator.

As a start, clean all the ground and make sure there is NO paint between the grounds and metal. (Sorry about the nice paint job!). This includes battery- to block and block to firewall. This especially includes the regulator case and where it bolts to the chassis. Resistance anywhere will cause voltage drops that will show up almost 1 to 1 as higher regulated voltage.

The difference between the voltages at battery+ and the + feed to the regulator (the blue wire in the stock system) should be no greater than 0.3volts ideally, 0.5 volts difference is tolerable most times. If this difference is higher, then there are voltage drops in the connections, wiring, and perhaps ignition switch that have to be corrected. If you do not, there will always be excess charging voltage.

BTW, on a street machine, 14.5 volts will not fry you battery. It is just a bit above the old Mopar system standard which is 13.7 to 14.3 volts measured across the battery terminals at fast idle and warmed up, and with the battery well charged. 14.5 volts common on many newer cars.
 
I went to a 100 amp one wire chevy alternator with the regulator in the alternator....one less item on the firewall...less wires....chrome case and 100 dollars....good deal I believe
 
Hi nm9stheham... I can't remember exactly where I tied into the 12+ source for the AutoMeter Volt gauge. I will have to run that one down.

I installed a new PowerMaster 75A, Model: #17508 Alternator, that features a double field output, but I am only using 1 field with my setup.

I must now checkout ALL of the voltage values and the grounding issues, that you have kindly mentioned. Thanx a bunch, for all the info!

- - - Updated - - -

Hi terzmo.... A few years ago, when I was gathering up all the new parts for my resto project, I had considered going with an all-in-one alternator, like you mentioned,
that would effectively have eliminated the external regulator, extra wiring and related issues. However, because I was also installing March's custom mounting brackets
and pulley systems..., I wanted to stay with an alternator case, that would give me the least amount of grief lining up all the pulleys. Your idea might have worked fine,
and not knowing any better at the time, I didn't want to take that chance.
 
A volt meter shows the condition of the battery, not the rate of charge. 14.5 volts is fine. You don't have a problem...
 
A volt meter shows the condition of the battery, not the rate of charge. 14.5 volts is fine. You don't have a problem...
Not exactly. Battery voltage without any charging going on and with the battery 'rested' (i.e., with the internal surface charge dissipated that occurs during charging), the voltage of the battery by itself is an indication of battery condition. When charging is going on, the battery can be pretty crappy (with high internal resistance for example) and a properly regulating charging system will still put the same voltage on it. Only when there is a shorted cell in the battery (causing excess charging current) may the charging voltage be dragged down.... some. So the 14.5 volt reading is much more an indication of where the charging system is trying to regulate, and charging system health, and not so much battery condition.

With the supposedly low output (13.5v) regulator, I would check out system for any voltage drops. That set of checks is wise IMO for ANY of these older cars; it is a known problem area.

As for the best regulator, I would try to find an NOS flat pack regulator (the last unit pictured by the OP); the new stuff is rather 'iffy' anymore. But the wiring to the alternator field connection needs to be changed; the OP has a 2 field connection alternator so that is a good start.....
 
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