Voltage Regulator Choices

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jonn6464

jonn6464

1970 Duster
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Hey FABO,

I'm in the market for a new voltage regulator.

It seems there are a number of options, all at a different price point.
Can anyone offer some sound advice on the differences (other than Made in China vs USA) on these units. Some are $15, some are $80.

Here's some units listed on Amazon, just for reference to the different prices.

I need this for a 1968 318LA motor, 4 speed trans, 100A alternator, after market stereo, Holley Sniper EFI.

Thanks for any replies.

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I assume you've done some sort of conversion? A '68 model would not have come with a regulator like the ones you show. They're for a '70-up system with a 3 wire alternator.......still not for a 100 amp alt.
 
Correct me if I'm wrong, but the voltage regulator only regulates the voltage not the Amps..That's why when your lights are dim voltage is only 12 volts or less.
 
Make sure you have the wiring to support 100 amps so it won’t fry your bulkhead connector.
 
cudamark said:
I assume you've done some sort of conversion? A '68 model would not have come with a regulator like the ones you show. They're for a '70-up system with a 3 wire alternator.......still not for a 100 amp alt.
Click to expand...
It's a '75 Trailduster with a 318 from the 1968 model year. All new wiring throughout, most of it upgraded sizes. The alternator needs to support the stereo, EFI, and aftermarket A/C system.
 
mbaird said:
Make sure you have the wiring to support 100 amps so it won’t fry your bulkhead connector.
Click to expand...
I've removed the ammeter and change to a volt meter. The thick battery and alternator wires that originally connected to the ammeter at the dash are now joined via busbar at the firewall. They won't pass through the bulkhead connectors at all.
 
Use the proper style that came with the year model. Get older NOS or good used. None of the new stuff is worth a damn.
 
I would get any one of the ones pictured in post #1. They are all solid state & more reliable than the original ones that were electro/mechanical & had moving parts that could fail.
 
not to hijack...but why in the world do guys remove the ammeter for a voltmeter?
 
OK..i didn't realize they were by-passing the bulkhead altogether. Still you have no idea what your current is?
 
ir3333 said:
OK..i didn't realize they were by-passing the bulkhead altogether. Still you have no idea what your current is?
Click to expand...
2 sided coin, current or voltage? Your choice.
 
ir3333 said:
not to hijack...but why in the world do guys remove the ammeter for a voltmeter?
Click to expand...
For me, it came about because I was replacing the gauges and I needed to make a custom set up. The aftermarket gauge set did not have an ammeter.

And yes, a secondary concern is melting the plastic on the bulkhead connectors.

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ir3333 said:
OK..i didn't realize they were by-passing the bulkhead altogether. Still you have no idea what your current is?
Click to expand...
Not all bypass the bulkhead. Some do, some don't

Sounds like the OP has redesigned the system to one that will work better with EFI. That's probably good. EFI needs a different approach because of how much it draws, and that it needs to draw from battery (at start) and then alternator when running.

But to answer your question about loads on a standard factory system.
For a truck that has a plow or winch on it - these devices, and particulaly the recharging of the battery can overload the battery line. On a standard alternator wiring harness, the bulkhead and the ammeter, along with the fusible link, will get hot - sometimes too hot - when subject to continuous loads over 30 or 40 amps.

lets take a plow - that gets run while the engine is running. They draw a lot so I've only seen the wired to the battery positive - some of the other guys maybe have seen some other arraignments.
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When the engine is running and the plow needs power, power is going to flow from the alternator at 14 Volts IF it can supply it.

If its 20 amps, the ammeter will swing 1/2 way over. 30 3/4 of the way.
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if we're also running lights, that too is coming from the alternator, IF it can supply it, but that doesn't show on the ammeter.

What will show on the ammeter is if the alternator can't keep supply the power. At least it can't supply it at 13 or 14 Volts.
Then the battery becomes the source of power. Maybe on 12 Votls but it can supply hundreds of amps - at least until it gets sucked down,
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Now when the job is all done, go hit the highway.
If the alternatoer wasn't spinning fast before to be near the top of it capability before, it sure will be now.
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And this is one way that the weaker/thinner/lighter parts of the system get hot.
It doesn't need to be a plow or winch. We see people too frequently charge a very low battery using the alternator. If the ammeter is pegging, that's a big clue to shut down and figure out what's wrong.

Here's what 20 minutes of charging at over 20 amps did to the standard ring terminals of one A-body ammeter.
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There were some heavy duty options but even so, really dont want to be pegging that meter.
 
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