Ammeter bypass

[440roadrunner]

Okay...need to ask a dumb question...

I have a copy of the 'fleet/taxi' wiring bypass diagram. It's also for 64s, like I've got. Question is on the regulator. Even on the 64 wiring, the fleet diagram shows using one of the later transistorized(?) regulators. Is that a must, or will the bypass work using (lol) one of the regular regulators???

The type of regulator has nothing to do with the output circuit. It IS "required" to use a solid state regulator with a Mopar breakerless ignition. Having said that, most if not all replacement 69/ earlier regulators are actually solid state.

What IS relevant to the regulator is voltage drop between the battery and the regulator. "Fixing" the output circuit drop (bulkhead connector and ammeter problems, AKA Mad) fixes part of the problem, but ANY drop between the battery and the VR will cause that drop to be ADDED to the charging voltage.

The general (factory stock) circuit path is battery.........starter relay.......fuse link.........through the bulkhead........through ammeter.........to harness welded splice..........to ignition switch connector........through the switch.........back out the switch connector (on IGN1)..........back through the bulkead.........and to ignition and VR Ign terminal.

So ANY bad connections in this path all added up is the voltage drop, AND anything in the GROUND circuit. This is easy to check. Key in "run" engine stopped. Measure between battery POS and the VR ign terminal. That reading should be VERY low, the lower the better. That is the voltage drop on the "hot" side, and should be less than .3V (3/10 of one volt)

==========================

Check ground side, engine running and charging, fast idle, and warm. Stab one probe into the top of the battery NEG post, and stab the other into the VR mounting flange. Voltage should "lower the better," below .2V and zero is perfect.

 

[furyus]

Not sure where people get the" you must have the electronic regulator if you have electronic ignition. "
I have run electronic ignition with the old style regulator
on both my 64 Sport Fury, and currently on my 69 Dart.
No issues.

 

[440roadrunner]

Not sure where people get the" you must have the electronic regulator if you have electronic ignition. "
I have run electronic ignition with the old style regulator
on both my 64 Sport Fury, and currently on my 69 Dart.
No issues.

Me neither which is why I put it into quotes. Having said that, there is really no reason to run a mechanical regulator over and above some sort of quality replacement solid state, which are far more accurate and reliable

 

[miller]

Thanks for the explanation, 440roadrunner!

Considering all options.

 

[440roadrunner]

Maybe I can boil this down, "in general" what you find in these old girls

1.....The numbawh whon problem is that the terminals in the bulkhead connector were NEVER designed for the kind of current they carry, even the original 30-some amp alternators were "on the verge." Even Ma knew this, which is why "fleet / taxi" wiring came about

I used to service HVAC, and they used these connectors in electric furnaces, which are typically 20A per heater element. THEY DO FAIL at 20A!!!

2...The ammeter is more minor and less likely. "What fails" The wire terminals can break inside at the terminals, and have. The nuts get loose. The ammeter ITSELF can fail internally, and is MUCH more likely on the cars with an all--plastic dash casting. The terminals are not originally really "fastened" to the guts of the ammeter. The only thing keeping the entire thing together electrically is "the nuts."

Read the Mad article. The ammeter they have pictured (melted) is exactly what I used to see around here on pickups with snowplows (electric hoists)

3...In harness splice. This is quite rare, but in my lifetime I've found or been party to as many as EIGHT. First one I found was in the early 70's in a friend's 68 RR. The ammeter was all over the map. We tore it down in his apartment parking lot. He didn't think we'd ever get it together. I was using the shop manual for my own 69.

4...VOLTAGE DROP in other connectors. This includes just about ANY connector, the more current the worse it is. Ignition switch, heater switch, and headlight switch are probably the worst. On later cars which have the engine harness disconnect (the white plastic around 73?) THAT THING is a problem

Voltage drop (or just plain bad / intermittent) in your ECU or voltage regulator connector is very possible

5...Voltage drop in switches. The biggie for charging voltage is the ignition switch itself because it feeds the VR sensing line (ign). One way around that is to use the switch to trigger a relay, and feed the underhood loads off a relay

VOLTAGE DROP between the battery and the VR is the number ONE reason for over voltage on charging systems.

6...Problems with grounding. Essentially, what it comes down to, is the battery, the engine, and the body, all need to be firmly (electrically) connected together. The OEM grounding was poor at worst, and marginal at best. Instrument clusters are notorious, and generally, you should add a ground pigtail. The ECU and VR MUST be grounded.

Grounding gets even more fussy with more and more electronics, such as breakerless ignition and EFI, because you get into electrical noise problems, "EMI"

Frankly, EMI on a modified platform can be VERY difficult. The OEM spent milllions of dollars designing and testing and even they have problems, sometimes.

 

[miller]

Swallowing hard on all that! No wonder I don't like wiring.

But, on my deal, probably going to do a bunch of change-up, anyway. 64 Ply...never liked the stock gauges, since no oil pressure. Still thinking on making my own panel. Of course, that will change much of the wiring there.

Just me, but don't think much on 'electronic' stuff. It's all something you must replace when it goes out. I'll hang on to the parts I can repair, like the mechanical regulator. Probably don't think much on that...but it's okay. Yeah, I'm a old guy.

 

[440roadrunner]

64 Ply...never liked the stock gauges, since no oil pressure. Still thinking on making my own panel. Of course, that will change much of the wiring there.

At least some of what we are discussing here MAY NOT apply to your 64. I believe the 64/65 had quite different feed-throughs for the ammeter wires. Look at your bulkhead connector.

 

[miller]

Exactly. From the start should have never been wired through the bulkhead connector, meaning the ammeter wires.
As far as I know, back then all were wired alike, except police/taxi stuff.

That's the main thing I'm looking at...getting rid of those connectors.

Just a weak spot in the system. There's ways to get around those issues. Though I have to make my picks on what various gauges I want, and how I want them wired into the harness. Can make it all complicated, considering the way all the behind the dash wiring is done, a handful of items wired together. Just a matter of breaking done each system, and going from there.

Will say though, I'm listening, and thanks! This old dog can learn new tricks.