Some of you already know about how my HEI module took a dump a few days ago. Well in the course of my troubleshooting, I found out that if an HEI module doesn't get full battery voltage, it can fail prematurely. This is what I think killed my HEI module, coupled with the fact that it was an Accel box.
Anyway, out of curiosity, I checked my battery voltage and my voltage at the coil (which, obviously, is the voltage also going into the HEI module) and the coil was almost exactly 1.5V below the battery's voltage. So I got a Tyco relay and wired it up to be triggered by the factory coil+ wire and send full battery voltage via a (15A fused) 12AWG wire directly from the battery to the coil+ terminal. Once I got it all cleaned up and reset the timing due to installing a brand new distributor, it ran beautifully. Felt like a much stronger, more stable idle and when I took it on the highway, it felt like it could accelerate a bit better when I romped on the gas. An earlier road test around the block on base didn't feel like there was any significant performance improvement, but whether there is or isn't, my goal is extra reliability of the HEI module and coil.
Now, while driving the car around today, I noticed that with a wire feeding the coil and HEI module directly from the battery, there looked to be more current draw on the charging system, as (at idle) my ammeter would steadily pulse between the two center lines in rhythm with the engine. Just a hair above idle and it remains steady at dead center. The same thing happens with the lights on, only in that case, at idle, the ammeter will hold steady just barely in the negative range. I can see the "idle pulsation" in my headlights as well. But once I hit the gas, everything's got full power.
Just a few interesting things that I found out and wanted to share. Once I finally get some free time, I'll write up an article on adding the relay, since I've got a pretty good feeling that it's going to end up an important part of anyone's HEI conversion.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Hi

Your Article will be help full please ! I bought a GM module, fitted it to a heat sink, bypassed my ballast, and viola! One hell of a improvement!


The pulsing you experience - are you still running an old style points regulator? If so what is the AC component of the voltage delivered - put the meter on AC - it will give you an idea where the reg cuts in and drops out

Got hold of a Echlin electronic reg that looks like the original points type- I am busy with a restoration - BUT gives me 13.85 solid at idle or max rpm -and the pulsing lights are gone

I also cobbled together a 5v plug-in reg for the dash - now my gauges are nice and stable


the HEI will be hidden soon - maybe just inside the firewall?

In North America and Australia, the single-field charging systems and points-type regulators were gone after '69. His car's a '74 or '75, can't recall which.

Jopapa- assuming your regulator and alternator are in good shape (can't remember what you're running), you may see smoother charging if you'll run a ground loop from the alternator housing to the regulator base to the battery negative.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I'll give that a shot and see what it does. I have no idea how old the voltage regulator is either, so I'll probably change that out in the near future.

While on the subject of voltage regulators, what part is used with the newer Denso alternators? I found a 94A alternator, but every vehicle it's listed for (and specifies "externally regulated") has no listing for a voltage regulator.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

The regulator was moved into the engine control computer on most all Mopars by '88, many before then. The type of regulator you have now will work fine with the new alternator, and hookup is the same.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

SlantSixDan,
Are you saying it is ok to run the newer 80's style alternators on our 74 Darts/Dusters? or are we stuck with the stock 35 amp units?

I recently bought a new MOPAR regulator from Summit which works better than the original one, but in gear at 600 rpm it does drop down to 12 volts and flickers a little, but not like the old original unit. It would swing below 12 volts to 9 and at 750 rpms go as high as 15.5 volts. With the new one from Summit, out of gear at 750 rpm I am at 13.6 - 13.8 volts.

Questions: If it is ok to run an 80's unit with the new stock style 70's regulators, Will the higher output alternators stop this voltage drop?

or is that just a function of rpm.

Will the "ground loop you suggested stop the slight flicker? or do both, adjust the rpms and ground loop?

This winter when it's 20 degrees and the lights, wiper, radio and heater are on and your in stop and go traffic, what do you suggest?

Just crank up the rpm's? or go for the newer 80's alternator?
I will do the ground loop as you have suggested.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

They're fully electrically compatible with the older voltage regulators, which is true clear back to the first '60 Valiant. They are not quite mechanically compatible, because different brackets are required. Neither are they fully electrically compatible, because with an alternator capable of significantly higher amperage than the original, you run the risk of damage to the ammeter and related circuitry. This damage can be extensive and catastrophic in extreme circumstances, so to run a high-amp alternator safely, upgrades to the car's main circuit are the common-sense thing to do.
The Mopar alternators our cars came with from the factory were, over the years, made in variants producing from 27 to 80 amps.
Generally not a good pick these days, from a reliability standpoint. Which is a shame, because the Mopar "restoration" regulator (black w/yellow inkstamp) really looks nice. A Standard/Bluestreak #VR125 or NAPA Echlin VR-38 is a better pick. As an aside, I do not understand why it is seemingly so popular to pay Summit's inflated prices for repair parts that are available locally for less, and without shipping costs.
Dimming at idle is characteristic of many — but not all — of the Mopar alternators made before the change to a higher-draw rotor. Don't have that date in memory any longer, think it was in the late 1970s. I can find out. It is generally not a function of having an alternator of too low maximum amp capacity. In fact, many of the higher-amp alternators have poorer low-RPM output than many of the lower-amp alternators. There are also many different pulley sizes, from 2-1/2" to 3-1/2". Larger pulleys aggravate the dimming at idle. Smaller pulleys reduce it. "Remanufactured" alternators are notoriously poorer than rebuilt originals.
That's quite good. Doesn't sound like you have too much of a problem.
Which "80's unit" do you have in mind? The '89+ alternators (Bosch, Nippondenso, or the Chrysler type w/black plastic rear cover) are the ones that need different brackets and all have output high enough to require a main circuit upgrade to prevent damage. Up through '88, variants of the older Chrysler finned-case alternator were used. These will fit right on as long as the pulley type is correct, but again, some of them have high enough capacity to warrant circuit upgrades.

But all of them will work just fine with the car's original type of regulator.
It often does.
Depends on how much effort you're willing to put in!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I have converted my 63 and 65 to the dual field charging system with the flat pack regulator and have experienced nuthin' but solid charging ever since. (Even at a stoplight with highbeams, stereo, blower motor, blinker, and cig lighter going!) It's an easy conversion and can be easily mounted in the stock position. Just my 2 cents.

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. . . there was good sport at his making.

Got a pic of where you mounted the regulator? The flat one doesn't fit well in the old spot on my '66.

Thanks,
John

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66 Barracuda 225 auto

Well with the addition of a ground loop, my ammeter still bounces at idle in sync with the ignition. I think the coil (MSD Blaster 2) just draws too much too quick and for too short of a time when it cycles for the voltage regulator to keep the charging perfectly even. Maybe with the addition of a later model 94A alternator, it won't be so noticeable. On the other hand, I did some wiring cleanup and made new battery cables, so once I have a new alternator and beef up the charging circuit, power won't be an issue at all.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me