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Index of Section Topics…

Section 1…“Alternators 101”
Quick in Vehicle test for troubleshooting alternators
Electrical flow thru conductors
Magnetism and induced voltage and current
Electromotive Force (EMF) and its role in Alternators
Rotor, Stators and their role in Alternators
Basic overview of the alternator and how volts/amps are generated

Section 2…”Delco 10-SI and Delco 12-SI Alternators used in our Jeep applications”
Delco 10-SI external front and back photos
Delco 10-SI internal cut away view
Delco 10-SI Dimensions
Delco 10-SI Amps vs. RPM Chart
Delco 10-SI Electrical connections
Ni-chrome Wire to replace your existing resistor wire (source to purchase)
Delco 10-SI and 12-SI Regulator Circuit diagram and circuit theory
Delco 12-SI external front and back photos
Delco 12-SI internal cut away view
Delco 12-SI Amps vs. RPM Chart

Section 3…”The CS-130, CS-130D and CS-144…now referred to as “Generators” by Delco!
Delco CS-130 Front and side views
Delco CS-130 internal cut away views
Delco CS-130 Case
Delco CS-130 Slip ring end frame internal and external components
Delco CS-130 Rotor, Stator and Rectifier checks with an Ohmmeter
Delco CS-130D external picture
Delco CS-130D external dimensions
Delco CS-130D Amps vs. RPM Chart
Delco CS-130, CS-130D, CS-144 OEM amperage ratings
Delco CS-144 external picture
Delco CS-144 internal cut away view
Delco CS-144 Amps vs. RPM Chart
Original U.S. Patent information on CS-130 All Silicon Voltage Regulator (ASVR)
Early versions of the CS-130
Iceberg Upgrade Kits for the CS-130
Iceberg Upgrade Kits to up amps to 140Amp output
Delco CS-series Regulator/Rectifier
All Silicon Voltage Regulator and Application Specific Voltage Regulators
Delco ASVR and two different wiring diagrams
Voltage divider circuit to fine tune Voltage Regulators
Bench Testing set-up for testing Alternator

Section 4…”Some practical upgrades for the do it yourselfer (DIY)”
Delco CS-Series Alternators “S-I(F)-L-P” Regulator Plug
Delco CS-Series Alternators Removal/Installation Step by Step procedure (VERY IMPORTANT TO FOLLOW!!!)
Delco CS-130 and CS-130D Regulator/Rectifier Plug terminals and designations
Heat issues
What actually fails internally when an alternator goes bad
Re-manufactured alternators
Aftermarket supplied components
Suggested over the counter replacement alternators for your Jeep
Delco SI-CS Wiring harness conversion plug picture
Delco SI-CS Wiring harness conversion plug and part numbers for other aftermarket suppliers

Section 5…“How to Guide” upgrades for you penny pinchers out there…”
Very general and generic “How to Guide” for those pick-n-pull folks with bone yards near them

Section 1…“Alternators 101”

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By the way, what IS a good, easy, simple, semi-foolproof method for testing one’s alternator?

That anyone can do?

No training required and only a valid Drivers License may be required, and perhaps an AM radio.

Well, at night one may pull up to a wall with one’s headlights on High Beam, turn off everything else that is drawing power, and have the vehicle at idle.

Sit there for about a minute noting the brightness of the headlights.

Kill the engine, and note the change in headlight intensity. You should notice one of the follow three occurrences…

1…. Headlights get brighter when the engine is killed…The alternator is not putting enough charge into the battery, when the engine is killed, there is less load on the battery and therefore more battery amps are available, so the lights get a bit brighter. Alternator requires service.

2…. Headlights get dimmer when the engine is killed…the alternator is keeping up with the demand that the headlights are putting on the battery, and is charging normally. When the engine is killed, the headlight continue to draw from the battery, however the battery is no longer supplemented by the alternator, and therefore there is less voltage/current that is being delivered to the headlights, ergo the lights get dimmer. Alternator is operating normally.

3…. Headlights do not change in intensity…Congratulations, that is some battery you have…Optima perhaps?

Alternatively (pun intended), a faulty diode may induce interference in the RF Frequency, or RF noise range, and this might induce an audible whine on the AM radio, very easy to check when you find that the battery is being discharged overnight.

So, while doing the above headlight testing, when the engine is running at constant rpm’s, turning off/on the headlights will put a load on the alternator, and at constant engine speed if you detect an AM radio interference that comes and goes with the additional headlight load, this may indicate that the regulator circuit (diode/s) is suspect.

If you vary the engine rpm’s, and the AM Radio Interference tracks the engine speed, then perhaps the bearings or the belts need servicing, or this problem might even be the spark plug wires or the noise suppressor circuit gone bad.

Unplugging the alternators regulator circuit may halt the RF interference; this is a pretty good indication that the Regulator circuit (diodes) is to blame. Some manufacturers recommend disconnecting the battery first, so please be aware of the recommended procedures and follow them. Do not EVER disconnect the battery cables when the engine is running, this is no longer a viable way to test alternators and will ruin many of the versions that are in use today.

In the diode rectifier circuit, the alternating current ripple voltage might be measured with AC multimeters, you should probably go out and do a quick measurement across the battery terminals to log a “normal” reading when you have a known good alternator and regulator for A/B comparisons at some later date, when you suspect that there might be a problem.

Less than optimal connections may also result in high impedance, which in turn, might increase RF noise.

If you understand/don’t care about the electrical characteristics of how magnetism is created in field windings and harnessed for use in alternators, please go ahead and skip this portion, and move on to “Section 2”.

Otherwise, read on for a brief discussion of what is happening in the world of electricity, electronics and regulators, field magnetism, diodes and how it all comes together to keep our FSJ’s squared away. This is not very technical, and is pretty generic, to boot.

By the way, even the best minds in science do not know what electricity really is, what we do know is how to harness it, but nobody really can tell you what “it” is.

We can quantify, measure and harness it, but we are just not positive what holds those pesky electrons/protons together.

I find this somewhat refreshing.

When an electric current is passed through a conductor, a magnetic field is generated which surrounds that conductor. The reverse is also true, in which a conductor which moves across a magnetic field develops a voltage potential on its windings or wire conductor.
Current will flow if a complete electrical path to ground is provided.

This is a physics property that occurs in metallic structures, covalent bonding has a lot to do with the nature of the electron flow, go figure….
This electron flow is a principle of Electromagnetic Induction (EMI), and is a method of inducing a voltage in a wire that is passing thru a magnetic field.
To further illustrate this physic’s principal, imagine two bar magnets placed end to end, the North Pole on the first magnet facing the South Pole on the second magnet. You now have set up a magnetic field that is present in the space between the magnets.

Passing a length of wire through this space will “induce” a voltage. This is termed (oddly enough) an “induced voltage”.

How much induced voltage is dependent on the length of the wire (wind that wire around a bobbin and you suddenly have a lot of wire) that is passing thru the magnetic field, and the rate of speed that the wire achieves when passed through that magnetic field. Additional wire would mean additional voltage, and therefore additional current, all other things being equal (namely the magnetic field’s intensity in this case).

The wire moving through the field may take on different shapes. It might be a straight wire, or perhaps a coil or loop of wire, or even loops of wire. The longer the length, of that wire passing through the magnetic field, the greater the voltage induced on that wire.

An increase in the magnetic field, will also produces an increase in the induced voltage. Also, the greater the speed at which the wire moves thru the magnetic field, the greater the voltage that will be produced (induced).

It doesn’t much matter if you move the wire or move the magnetic field, both activities will generate a voltage. If the magnetic field is increased, an increased voltage will be induced, if the magnetic field is reduced, a reduced voltage will be induced.

As Scotty of “Star Trek” fame was fond of saying…”Ya cannot change the laws of physics, Captain…”

Due to the magnetic fields physical properties, these electromagnetism’s have lines of magnetic force that flow from the North Pole to the South Pole.
The magnetic field that is developed and surrounds a current-carrying conductor can be visualized as spreading in a radial pattern outward from the conductor. Much like ripples of water when a stone is dropped into water, however the “ripples” of a magnetic field need to complete their path, and they always attempt to return to the magnetic structure from whence they originated.

Now, just as in magnets, like charges repel each other, and unlike charges attract each other.

Those magnetic lines repel each other, the stronger ones are the ones nearest the magnetic poles, since they repel other lines of magnetic force, other lines are moved further away, and so on and so forth.

So, getting back to how all of this works, we find that as we manipulate the speed, the distance, or the magnetic field strength applied, the resulting induced voltage corresponds in a like fashion.

Make a fist with your right hand, and do a “thumbs up”, and hold your fist in front of you, now extend your forefinger like you are pointing at something, the forefinger and the thumb will be at a 90 degree angle from each other. Now if you take your right middle finger and make a 90-degree angle with the forefinger, your middle finger will be pointing to the left across the chest area.

Holding the fist in this orientation, and not moving the position of the fingers and thumb, if you point your thumb in the direction that the conductor is going to be moved thru the magnetic field, and the forefinger in the North to South direction of the magnetic flux, the middle finger will point in the direction that electron current will flow.

If we increase the magnetic field, then the conductor cuts through an intensified field for a given distance traveled, thus increasing the induced voltage. A stronger magnetic field has its lines of magnetic force more tightly bound. Increasing the number of lines of magnetic force that are cut in a given distance and time, increases the induced voltage.

The laws of physics (“… Aye, Captain!…”) also indicate that changing the angle of the conductor that is passed through a magnetic field will influence the induced voltage, correspondingly.

A 90-degree angle has been shown to create the greatest induced voltage. By 90-degrees, we are referring to perpendicular as, for example, a knife slicing a bread loaf. The further one deviates from this 90-degree angle, the smaller the induced voltage.

This is similar to slicing that loaf of bread, if we cut it at an angle, the knife has to travel longer to cut thru the same vertical distance of the loaf, and transferring this “bad analogy” to the alternator, magnetic lines of force can be cut at 90 degrees, and thus travel a shorter distance in a given period of time. Thus they cut more magnetic lines of flux in a shorter time frame, thus generating increased voltages. Cutting that loaf of bread at a greater angle cuts the same number of magnetic lines of force, but the blade has to travel a greater distance, and takes a bit longer to complete.

Another interesting physics property to note is that if we reverse the conductor back and forth thru the magnetic field, the voltages that are induced will reverse and we note that the induced voltages will be of opposite polarities from each other.

One direction thru a magnetic field might induce a positive voltage, and reversing that same conductor (the opposite way) thru the magnetic field produces an induced voltage that is of the opposite polarity. Even though there is no change in the conductor, or the magnetic field, only in the direction of travel.

So, moving a conductor back and forth thru a magnetic field causes voltages to be induced and the voltages will be of opposite polarities of each other.

In review of these basics, we can state the following…

The greater the speed of a conductor that is moving thru a magnetic field then the greater the induced voltage that will be generated.

The longer the conductor then the greater the induced voltage that will be generated.

The denser the magnetic field then the greater the induced voltage.

The closer to 90 degrees that the conductor cuts across the magnetic lines then the greater the voltage.

Another way to put all this is to simply state that:

The induced voltage is directly proportional to the rate of speed of the conductor that it is cutting through the magnetic lines of force, all other things being equal.

In this sense, the rate of speed can also be tied to the number of magnetic lines of force that the conductor passes thru in a given time frame. Increasing the speed or length of the conductor or magnetic field strength will all result in increasing the induced voltage.

The same can be said of the opposite, reduce any of the properties mentioned, and the induced voltage will be reduced in direct proportion.

If the conductor that the magnetic field is passing through is part of an electronic circuit, then current will flow in proportion to the induced voltage. The induced voltage creates the current flow, and if you can find a way to prevent the voltage from rising, then the current has to increase, limit the current and the voltage needs to rise.

An alternator has a coil of wire wound around a Ferro-resonate material. In this manner, an electro magnet is created, because DC current/voltage is applied to this coil, current flows thru it, and they create a magnetic field. This magnetic field is polarized, which simply means that it has a North Pole and a South Pole. This is essentially the rotor, and as it rotates, its magnetic field cut the Stators coil windings, by creating a whirling magnetic field.

When a current-carrying wire is wound into a number of loops to form a coil, the resulting magnetic field is the sum of all of the single loop magnetic fields added together. Increase the loops making up the coil, and you increase the magnetic field.

In review, the rotating core of an alternator has an iron core, which is called an armature. This rotor or armature has copper wire wrapped around it. Passing 12Vdc to this coil of wire, results in direct current flow, which in turn produces a magnetic field and magnetizes the iron core, thus making the magnetic field denser. The rotor is heavy and is supported in the alternator housing via front and rear bearings that support a shaft, outside the alternator, a pulley is mounted on this shaft, to engage the alternator belt, which is driven by the pulley on the crankshaft.

The stator of the alternator is made up of three loops or coils of wire that are mounted to the housing of the alternator, which are stationary. The rotating magnetic field whirls through these coils of wires inducing three voltage waveforms. Now, since this rotating mass is changing the angles of the field strength (magnetic field) as it rotates, the induced voltage and the current that these stator loops carry vary accordingly.

So, now we have a dense magnetic field and as the engine speed of the vehicle increases, we can see how the density of that magnetic field increases. As this magnetic field is rotated, an induced Electro Motive Force is created in the three phase stator windings that are 120 degrees apart.

Here is a hint…want to know if the brushes on the alternator need replacing, put a screwdriver against the alternator, being careful not to get it hung up on anything, and check out the magnetism that the alternator puts out. With time, you can “feel” the difference in magnetism intensity, and judge “good” brushes and “bad” brushes.

Image 001

Each stator loop coil creates a 360-degree voltage that is known as a sine wave. The induced voltage gradually increase until the angle is at 90 degrees (peak induced voltage and low current flow), and as the angles decrease again, the voltage decrease correspondingly (as the current increases); until the magnetic field begins to approach another set of stator loops or coils of wire, and the process starts all over for that particular loop coil, see the below picture to visualize this process.
Image 002

In our alternator example, we have three loops of wire, and these three loops are placed such that a sine wave in each loop is generated. A complete revolution of the rotor assembly, which is 360 degrees of revolution, gives us three overlapping voltages that are 120 degrees apart (360 divided by 3 equals 120). The configuration of the windings (and associated diode rectification configuration) causes these Alternating Current (AC) sine waves to overlap each other, as depicted below.

Image 003

Once the AC voltages are created, we need to modify them because our Jeeps run on 12Vdc. The battery is responsible for supplying power to the electrical loads, and the alternator is responsible for keeping the charge rate of the battery within design limits.

These overlapping sine waves have their negative going voltages blocked off by diodes, and thus we end up with a series positive humps of DC voltage. This is referred to as a full wave bridge rectifier, as you can see in the below image.

Image 004

Electronic components in the regulator circuit smooth out this voltage, in order to generate the 13.5Vdc to 14.8Vdc required by the battery for topping off its charge. The various regulators associated with alternators are responsible for this engineering feat.

We are generating the AC voltage needed, in order to rectify or alter it, to produce a voltage and a current that is sufficient to charge the vehicles battery.

The alternator is a three-phase generator with a built-in rectifier circuit consisting of six diodes in a full-wave bridge rectifier circuit. The DC voltage and current from the battery is supplied to the Rotor through the use of slip rings mounted on the pulley shaft.
In essence the diodes are solid-state switches with no moving parts, making them maintenance-free, until a failure mode is encountered.

When they fail, they usually short, either totally or partially. Partial shorts in diodes are referred to as “leaks”. Leaking diodes will allow charging of the battery, and when the vehicle is left sitting for a period of time, like overnight, the battery may discharge thro