Alternators
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. We think of them as putting out direct current as that is what our vehicles use, there is an additional portion of the alternator called the rectifier that converts that alternating current into the direct current our vehicles use. https://en.wikipedia.org/wiki/Alternator_(automotive)
Note: if you have recently replaced/worked on the starter(or alternator without disconnecting the battery) and your battery isn't charging, check the wire/fusible link going from the starter up to the alternator. Ensure it's in good condition, clean, and going to the proper terminal. Also see the starter page.
CS alternator connections/terminals:
Ground - Case ground needs to be clean and well connected.(required)
B/Batt - Large stud that goes to the battery(via the starter on our systems).(required)
L - Lamp, the most common used and required circuit. Battery voltage flows through a bulb(Charging Indicator Lamp) and resistor to excite the alternator.(required)
Note: Do not connect the L terminal directly to 12vdc unless you want to destroy the regulator. Incandescent indicator light bulb can be used or a resistor. The 4-pin regulators for the CS130D, AD230, AD237, and AD244 alternators require a resisted ignition wire to the L terminal to activate without blowing the regulator.
P - Phase, used on some diesels for a tach signal, can also be used for an hour-meter.(optional)
S - Sense, links to a high load location, monitors the voltage at that point to determine charging(optional)
Then you will have either an I or F terminal, but never both.
I - Ignition, backup turn-on voltage, can be used to excite the the alternator(optional)
F - Field, connected to the field positive, field strength sent as square wave to PCM(optional)
Example Wiring Diagrams:
Here is an example of the charging circuit on a 96 A/S Van, should be the same through 99:
2000 changed a bit, here is an example:
2001 and later look like:
Stock Alternators:
With common loads, the factory alternator works just fine and there is no need to upgrade.
12SI(Systems Integrated aka internal regulator), 6-1/2in mounting spread straight across, 56/66/78/94amp maximum output ratings
CS130(Charging System, 130mm)
CS130D Larger bearings, more open, 2 internal fans, reg and rectifier located outside
2005 Alternator https://amzn.to/33Y2Xcw
01-04 alternator https://amzn.to/2TkpdGs
2000 alternator https://amzn.to/2z9uDvi
96-99 alternator https://amzn.to/2Dr81JF
94-95 alternator https://amzn.to/2DJjIMT
90-93 4.3 alternator https://amzn.to/2DsYEsP
87-89 4.3 alternator https://amzn.to/2TiFonv
87-90 2.5l alternator https://amzn.to/2DIcbxF
86 4.3
86 2.5
85 2.5 and 4.3 alternator https://amzn.to/2DIqGSg
Alternator Upgrades:
Common reasons to upgrade to a more powerful alternator or adding an additional alternator are huge bass thumping stereo systems, charging the extra batteries installed into an RV conversion, electric cooling fans, emergency service vehicles, plow vehicles that spend a lot of time idling or at low RPM, and other specific vehicle uses. Stock vans under normal usage do not require a larger alternator.
The most common upgrade for our vans is to upgrade the stock alternator to a 130 or 145amp AD244, available in stock or upgraded outputs. I personally would stick with a stock 145amp AD244 for an upgrade. But a 160amp DR44 does sound nice as well. Don't forget to upgrade your wiring from the positive stud on the alternator.
AD244 130 or 145amp, plug and play upgrade from 4pin CS130D, larger case requires slightly - 1" longer serpentine belt
DR44 and DR44G is almost the same as the AD244(except you can't replace the negative diodes separately have to replace the rear case), can get a 4pin version, on the 2pin version the regulator can be swapped out to the 4pin version, the AD244 is more serviceable. Nice thing is that it is available in a 160amp version.
CS144 7-1/8 mounting spread straight across(early), and offset mounting(later)
Longer Belt:
With the AD244 style upgrade, you often need about a 1" longer belt, please measure YOUR belt. Here are some examples:
AC Delco GOLD https://amzn.to/4307sz8
Continental Elite/Gatorback https://amzn.to/3pUDw9r
Dayco https://amzn.to/45gXnQn
Gates https://amzn.to/3BFnsLg
D&D PowerDrive/Duralast/Generic https://amzn.to/3Ma5S6M
Wire upgrade:
If you are upgrading your alternator, you should upgrade the wiring from the alternator. Don't forget to upgrade your Fusible Link as well to protect your wiring.
12vdc 0.3v drop, measured length must include ground return. Example: 5ft positive from 145amp alternator to battery and 7ft negative cable = 12ft @ 145amp = 2AWG wire.
Alternator Connectors:
10SI alternator connector https://amzn.to/2BbT7W6
CS130/CS144 (dogleg)alternator connector https://amzn.to/2TeaKf7
CS130D alternator connector, same 4pin connector as the AD244 https://amzn.to/2FrYl4m
Alternator Connector Pictures:
4 Pin HD regulator for AD244 and to convert 2pin DR44G to 4pin(not needed if you get the 4pin DR44G)
GA722, 10458199, 19054622, D200XHD, D235SEL, 232665
AD244 - Remove AD244 regulator by unsoldering the stator connection and clipping the B+ lead. Loosen battery post nut a little to fit the regulator B+ collar. Crimp/solder the stator connection.
DR44G - Remove ~3/16” from DR44G mounting boss(left B-) causing regulator to sit uneven, may need a washer/spacer under DF, connect W to rectifier, trim plastic cover for wider 4pin connector.
You could get really fancy and control the 2pin PWM based regulator with an Arduino(looks like a fun project, but um, no) https://github.com/sparcules/DRuino44
