Overcharging

[Mattax]

Does that make sense to you?

Follow the current out of the alternator and look for where voltage could be dropping.
Assuming this is an early system...

Since the ignition feed is at 14.1 V, and the battery is at 13.5 V, my guess is the ammeter is showing a slight charge when you took those measurements. If so, modify the above drawing to show some current flowing to the battery.

If it is an early system, measuring voltage after the regulator is not as useful as measuring at the regulator.
Unlike the type shown in post #9, the earlier positive controlling regulator will reduce voltage into the rotor windings.

 

[Greg hailings]

Welcome to the forum!
Knowing the year and model will be very helpful.
Not all years were wired the same.


That's odd. With no current flowing, voltage should be either system voltage on the positive side or zero on ground side. Electricity can't flow since the wire is not connected.



That indicates there most of the resistance to flow is between the alternator's output stud and the main splice.
Does that make sense to you?

74 Dodge Dart

 

[Mattax]

74 Dodge Dart

OK. In that case, the diagram from post 9 will show the general scheme for your charging system.
Details that will or may differ, but not affect the concept.
Ignition circuit - when the key is on, the ignition amplifier (ECU) will draw power. There may also be a seatbelt interlock and some other gizmos. If there is an electric assit on the choke, it can also draw power when its on. I don't know the details off the top of my head.
If it was equiped with optional alternator and/or rear window defrost, wire routing will be slightly different as shown earlier in this thread.

 

[Greg hailings]

Follow the current out of the alternator and look for where voltage could be dropping.
Assuming this is an early system...
View attachment 1715402282

Since the ignition feed is at 14.1 V, and the battery is at 13.5 V, my guess is the ammeter is showing a slight charge when you took those measurements. If so, modify the above drawing to show some current flowing to the battery.

If it is an early system, measuring voltage after the regulator is not as useful as measuring at the regulator.
Unlike the type shown in post #9, the earlier positive controlling regulator will reduce voltage into the rotor windings.

When testing for voltage at the Field wire by putting 1 probe on battery positive one on field connection is it still suppose to be attach to alternator? I read that it shouldn’t be more than .2 volts? Just trying to make sure I’m getting a valid reading by pulling wire and testing.

I tested across the amp meter and got the same reading at both terminals as the ignition connection

 

[Greg hailings]

I’m thinking of doing the MAD conversion but want to make sure the Field is getting proper readings so I don’t get a drastic over charge when I go directly to the starter relay.

 

[Greg hailings]

When testing for voltage at the Field wire by putting 1 probe on battery positive one on field connection is it still suppose to be attach to alternator? I read that it shouldn’t be more than .2 volts? Just trying to make sure I’m getting a valid reading by pulling wire and testing.

I tested across the amp meter and got the same reading at both terminals as the ignition connection

And yes it was showing positive charge at amp meter

 

[Greg hailings]

And yes it was showing positive charge at amp meter

The connection I’m testing is the one that goes to I on the regulator as well as to the ignition.

 

[Mattax]

When testing for voltage at the Field wire by putting 1 probe on battery positive one on field connection is it still suppose to be attach to alternator?

Yes. This would be a test for resistance between the power supply and the regulator. Back probing at the alternator field connection is the easiest location since the regulator's connector doesn't allow that.

Just trying to make sure I’m getting a valid reading by pulling wire and testing.

It's not valid. With the wire off, there's less current flowing in the circuit.
Imagine it was a dedicated wire going direct to the power supply.
Remove the wire no current flows through. The voltage above ground should be the same as the supply.

Lets use an example with a lamp and a 12 volt battery.

If the second probe is to ground, the meter will see what voltage?
And if the second probe is on the battery's positive cable, then the meter sees what voltage?

Same example, with current flowing through the light bulb.

If the connections and wire are big enough and in perfect condition, the voltage at the bulb should still be battery voltage. Viewed the other way - there's no voltage drop in the wire.

But if there is a poor connection, or undersized wire, that resistance to flow will cause a voltage drop.

I read that it shouldn’t be more than .2 volts?

IMO. That would be really good.

I tested across the amp meter and got the same reading at both terminals as the ignition connection

You mean tested voltage - which implies one probe is on a ground (chassis).
Testing across the ammeer terminals should be zero. There should be no loss in the ammeter. Internally its a metal plate with the two studs pressed in. Unless the studs are loose, there's no measurable resistance.

 

[Mattax]

I’m thinking of doing the MAD conversion but want to make sure the Field is getting proper readings so I don’t get a drastic over charge when I go directly to the starter relay.

It's generally a bad idea.
It puts all the loads through an extra fusible link.
It puts all the current except battery charging on a long circuitous to the main splice.
If you are going to run electric fuel pumps, EFI, a winch, then reworking the system is really needed.
If you're running a 60 amp alternator, and it came that way, then you already have a pretty robust wiring arrangement. Just find the a problem spots.
If you are or will be running a 60 amp alt, or just to avoid the bulkhead connector weakness, there are better choices.
a. One is copy the factory 60 amp alternator wiring.
b. Another, easier method, is add a parallel wire from the alternator to the ammeter.
c. Last, arguably easiest, is to add a dedicated charging wire with fusible link from the alternator to the battery. The downside is this will result in the ammeter no longer seeing the charging current because there is a shorter route to the battery. Battery discharge ( starting and running without alternator) will show on the ammter 'cause its still the shortest route to the main splice.

 

[Mattax]

The connection I’m testing is the one that goes to I on the regulator as well as to the ignition.

OK. I think what your saying is this.

IF so, then there's a 1 V loss between the alternator output stud and the main splice -
and another 1 V loss between the wherever you're measuring the 14.1 and the field/regulator.
On the battery feed/charge line there's a .6 volt loss between the ammeter and the battery.
Check each connection and wire in between these and then clean or fix as needed.

ECU,coil, and alternator's rotor probably drawing 6 amps.
Guessing the battery is only drawing a couple amps.
The ammeter show 40 amps to 40 amps. Zero in the middle. A low battery will suck current when supplied power 13.5 Volts. A fully charged battery will not suck any power at 13.5 Volts. If its drawing more than 20 amps and doesn't drop back quick, then go charge it on a charger. That's when stuff gets damaged. Can't be drawing 30 plus amps through these wires for long periods of time without some connection or the link starting to melt.

PS. If the battery is taking 20 amps charging and there's only 0.6 Volt drop, that's pretty little resistance for that amount of flow. I'd still visually check the connections.

 

[Greg hailings]

Yes. This would be a test for resistance between the power supply and the regulator. Back probing at the alternator field connection is the easiest location since the regulator's connector doesn't allow that.

It's not valid. With the wire off, there's less current flowing in the circuit.
Imagine it was a dedicated wire going direct to the power supply.
Remove the wire no current flows through. The voltage above ground should be the same as the supply.

Lets use an example with a lamp and a 12 volt battery.
View attachment 1715402303
If the second probe is to ground, the meter will see what voltage?
And if the second probe is on the batteries positive cable, then the meter sees what voltage?

Same example, with current flowing through the light bulb.
View attachment 1715402305
If the connections and wire are big enough and in perfect condition, the voltage at the bulb should still be battery voltage. Viewed the other way - there's no voltage drop in the wire.

But if there is a poor connection, or undersized wire, that resistance to flow will cause a voltage drop.
View attachment 1715402308



IMO. That would be really good.
You mean tested voltage - which implies one probe is on a ground (chassis).
Testing across the ammeer terminals should be zero. There should be no loss in the ammeter. Internally its a metal plate with the two studs pressed in. Unless the studs are loose, there's no measurable resistance.

Correct I tested each stud to ground

 

[Slantsix64]

If your buying standard voltage regulators i had 3 bad out of the box heres a way to check them before you buy

 

[Mattax]

I read that it shouldn’t be more than .2 volts?

FWIW as a comparison.
Chrysler's test in the '73 shop manual is for less than .7 Volts drop in the main circuit (alternator to battery) with 20 amps flowing.
That test is done with a carbon pile to create a load.

Remember above I said if I drew what you described correctly, we see a 1 Volt drop between the alternator and the main splice?
That's a lot more than the Chrysler's test considers OK. That's 1 Volt drop with what? 8 amps? through one or two connectors.
Chrysler's test is .7 Volts drop with 20 amps going through all the connectors between the alternator and battery positive.

 

[Mattax]

Try to dig up a shop manual for '74.
This will give you a bit of head start., its based on a '73 which is similar. The factory diagrams for these years are little different than the earlier ones. So this should help you figure it out.

It is the same schematic as drawn above with some of the details revised to reflect the '73 Dodge shop manual's diagram.

Wires labels are usually like this:
A related to battery.
R for Alternator
J for 'Ignition' (which includes more than just ignition as you've probably noticed)

The number after the dash is wire gage followed by insulation color.

Open circle or square is a terminal connection.
Closed circle is welded splice.

Mymopar has some shop manuals digitized for pdf download.
You can also buy some good quality digital and print copies or even originals if you look around.

 

[Greg hailings]

I’m trying to find a 2 issue now smh
When checking voltage at ignition connector under dash I have some losing connection. If I move the group of wires just right car looses main power and dies. Assuming it’s the main red wire but could be going back towards bulk head

 

[Mattax]

Well the '73 FSM shows the power to the inition switch as red.

Be real careful moving wires around under there with the battery hooked up.
Everything connected to the main splice is hot - all the time.
Accidently ground any of them and BIG sparky. If they touch good, the fusible link will go poof!

It's been years since I've had a column ignition switch car, but some guys here with early 70s cars have posted about finding bad connections there.
If you need to replace a terminal connector in that one (or the bulkhead) search for a thread I started on Chrysler connectors and terminals. That should help.

 

[Greg hailings]

Looks to be an issue between Female and male connector specifically the large red main power wire. Had the problem about 8 years ago where it was sporadic about turning over and I replaced the ignition switch and it fired right up (thought problem solved) than sat in the garage until I got a wild hair to start working on it again. Since I replaced the female side that goes to the column I’m assuming it’s the male side that goes to the main harness (if you move the red wire just right it dies)

It did drop charge at alt to 14.78 volts
And battery voltage was 14.11

 

[Greg hailings]

 

[Mattax]

It did drop charge at alt to 14.78 volts
And battery voltage was 14.11

That makes sense.
I assume you understand that if the regulator 'sees' a low voltage on the J2B wire, it assumes that is system voltage and lets more power through the rotor.
So if the regulator sees 13.5 V, it thinks the system voltage is low, even if the alternator is producing at 15.1 V.
With the improved connection, the regulator 'sense' or controlling terminal is getting voltage much closer to what the alternator is producing power at.

 

[Mattax]

Again from '73, not '74, but looks like female connector is the harness side, and male connector wires go to the switch.
Often the female connector contains the male terminals, and visa versa.

Make sure the terminals are hooked into the plastic connector. If the barb on the terminal doesn't catch then it backs out and connection is poor.
The other thing to check for is the wire crimping onto the terminal.
Almost certainly have to remove the individual terminals to check that.
There's a small tool to slip over or behind the terminal to depress the barb so they can be removed.
@halifaxhops has a picture of a kit of different removal tools:
Sources for Chrysler type wire terminals

The round bullet type terminals I havent had to deal with.
Picture here:
Sources for Chrysler type wire terminals
@MomsDuster may have found more info since that post.

 

[Greg hailings]

Again from '73, not '74, but looks like female connector is the harness side, and male connector wires go to the switch.
Often the female connector contains the male terminals, and visa versa.
View attachment 1715402517

Make sure the terminals are hooked into the plastic connector. If the barb on the terminal doesn't catch then it backs out and connection is poor.
The other thing to check for is the wire crimping onto the terminal.
Almost certainly have to remove the individual terminals to check that.
There's a small tool to slip over or behind the terminal to depress the barb so they can be removed.
@halifaxhops has a picture of a kit of different removal tools:
Sources for Chrysler type wire terminals

The round bullet type terminals I havent had to deal with.
Picture here:
Sources for Chrysler type wire terminals
@MomsDuster may have found more info since that post.

I appreciate all your help!

 

[halifaxhops]

This style kit will remove 99% of the terminals on a car. Look on e bay for them

 

[don21771]

To check this, get your voltmeter as close as you can electrically to the VR. The ballast resistor power, or the blue alternator field wire are two points. Don't disconnect anything, leave all wiring connected "normal." Put the key "in run" with engine stopped. Stab one probe into the battery POS post, and hook the other to the power at the ballast. You are hoping for a VERY small voltage, the lower the better. Anything over about .3V you need to look into

The functional path in a stock harness is battery...starter relay stud...fuse link....through the bulkhead connector (RED ammeter wire) through the ammeter, out the ammeter on the BLACK ammeter wire, to the WELDED splice.....and branch off to the ignition switch connector.......through the switch......out the switch connector on the blue "ignition run" line....out the bulkhead connector.......and to the underhood loads, that is ballast, VR, alternator field, and depending on year model, electric choke and one or two smog doo dads.

The usual suspects are the bulkhead connector terminals, the ignition switch and the connector[/QUOTE] all seems good now finely installed new alternator now steady 14.3 volts...thanks for you adive..

 

[Steven190]

I have the same problem of overcharging. I have changed the amp gauge to a voltmeter. Also have a MSD ignition, so I do not have a ballast resister, I installed a terminal strip with the wires are connected to
What I am seeing is you start the car the voltage is 14, but when you increase the rpm the voltage goes to 16.
The test from the battery voltage to the Bark Blue wire has a 1.18 volt drop I have 11.6 at the strip. So I have a voltage drop in the ignition circuit somewhere.
My general question is if I am taking volts from the same place: to the regulator and to alternator, no matter what the volts are, should the regulator still work properly? Or does or get the difference from the battery side of the alternator? or from a voltage drop in the ignition side?
I am still chasing things down, this wiring has been butcherer way too much over the years.

 

[Mattax]

MSD igntion does not care if the ballast resistor is there or not. So its not a given than an MSD = no ballast resistor. You could have left it in, as I did.
In fact that's what the original instruction suggest - they also used to provide jumpers so in an emergency it was easy to use the oem system.

When starting a car, battery voltage should drop! If it doesn't go below 10 V, the battery is pretty good.

With the increasing voltage with rpm to 16 V - if it stablizes at 16 V by say 1250 rpm, then yes, its a resistance problem.

The regulator will work properly for the information it is given.
So to answer your question; Yes it matters where the regulator 'reads' voltage.

When there is excessive resistance in the lines leading to the regulator, it will see a lower voltage than the alternator is producing at.
The voltage drop through the resistance will vary with current. See post #33 if that doesn't make sense.

See the previous page about how a negative controlling regulator works.