Serp Alternator Ques

[keith61760]

Which year alternator will fit the serpentine setup that I have? I got the brackets out of a junk yard and am having a hard time figureing out the right alternator to fit the brackets. Thanks.

[keith61760]

Doing some more searching around (almost 2 weeks worth) I found someone mentioning using an alternator for a 94 C1500 4.3L. I found one and it says the case is CS130 and seems like the right one for the serp setup I have.
http://store.summitracing.com/partde...396+4294840129

[rockn30809]

Chevy truck from 89-95, 350 or 4.3 the brackets are the same for both.

[keith61760]

Thanks. Will be ready to fire back up soon!

[JohnC]

Looks like a nice clean setup you have there. Do you have a build thread going? What are the specs on the motor?

[TwinTurbo]

An 88 up F body serpentine system, you'll need. Any alternator that fits that application (88-92 Camaro or Firebird V8) will fit

It's the same as the later C4 corvette alternator. GM late model small case alternator. It should be a CS type, CS 105, 110, 120 160 and whatever there is out there. The larger ones (I think 110 and above) have better cooling. Also make sure you have the right housing, not all these can be clocked appropriately.

[keith61760]

Thanks for all the help and info.

John-No build thread yet. I have to sit down and resize the pics. Started out as a quick engine swap because the starter bolt mount on the engine was a hack weld job from the PO and finally broke. Its a GM crate motor with about 25k on it, put an Edelbrock Cam, intake carb and timing chain on and added the serpentine setup. Centerbolt heads and re-sealed the engine and transmission. Repainted almost everything in the engine and engine bay, transmisison and I am currently installing a new wire harness.

Just have to figure out the exhaust now and I should be set. Will have to do body and paint later. Needs new doors and fenders because of rust which I have already. Then paint and interior.

[JohnC]

Well it's looking good man, can't wait for more updates.

[gchemist]

Ditch the CS alternators. Install a AD-244.


145 amps! It bolts right in! I love mine. Power windows love the extra amps.
http://www.alternatorparts.com/ad_al...order_page.htm

The AD-244 come off late model trucks. Mine is off an 08 truck.

[keith61760]

Originally Posted by gchemist

Ditch the CS alternators. Install a AD-244.


145 amps! It bolts right in! I love mine. Power windows love the extra amps.
http://www.alternatorparts.com/ad_al...order_page.htm

The AD-244 come off late model trucks. Mine is off an 08 truck.

As you posted this yesterday we were in the garage installing the new CS one from Summit. D'oh!

[Manbearpig]

Originally Posted by gchemist

Ditch the CS alternators. Install a AD-244.


145 amps! It bolts right in! I love mine. Power windows love the extra amps.
http://www.alternatorparts.com/ad_al...order_page.htm

The AD-244 come off late model trucks. Mine is off an 08 truck.

Smart man

[keith61760]

Which is the right one to use? Just a mid 90's 4.3L? Thats the last piece of the puzzle. I hope.......................

[gchemist]

Depends on how many amps you need. Both work great. I do have one problem with mine. The internal regulators shut it down at high RPMs. My lights dim at night. Power is restored once RPMs go down. Power loss is noticed slightly at WOT. The alternator is over reving and cutting out. I need a smaller pulley on it or find another solution.

[keith61760]

Originally Posted by gchemist

Depends on how many amps you need. Both work great. I do have one problem with mine. The internal regulators shut it down at high RPMs. My lights dim at night. Power is restored once RPMs go down. Power loss is noticed slightly at WOT. The alternator is over reving and cutting out. I need a smaller pulley on it or find another solution.

I think that is the alt I will look into if I need to upgrade or replace. Thanks for the info.

[DirtyLarry]

Originally Posted by gchemist

Depends on how many amps you need. Both work great. I do have one problem with mine. The internal regulators shut it down at high RPMs. My lights dim at night. Power is restored once RPMs go down. Power loss is noticed slightly at WOT. The alternator is over reving and cutting out. I need a smaller pulley on it or find another solution.

Keep in mind the amperage is regulated by the ECM/PCM on the late model trucks, which could be why you are have that issues at high RPM’s on an non-GM LAN or J1950 communication data bus controlled alternator.

I ran into an issue similar to that on my 8.1L conversion where the alternator output was so inconsistent, I had to swap my AD series back to a pre-ECM regulated 124 AMP alternator as my marine engine control system does not support the alternator amperage regulation. Once I swapped to non-AD series the problems were solved.

From what I can tell, the link you provided is intended to convert late model GM trucks with AD-230’s to 244’s, which are both computer regulated. …not so much for converting the 244 to older vehicles pre-ECM controlled alternators.

I am of the opinion that for the sake of the thread starters question, he is better off with a CS alternator even though the later model alternators are a high quality piece.

[keith61760]

Originally Posted by DirtyLarry

Keep in mind the amperage is regulated by the ECM/PCM on the late model trucks, which could be why you are have that issues at high RPM’s on an non-GM LAN or J1950 communication data bus controlled alternator.

I ran into an issue similar to that on my 8.1L conversion where the alternator output was so inconsistent, I had to swap my AD series back to a pre-ECM regulated 124 AMP alternator as my marine engine control system does not support the alternator amperage regulation. Once I swapped to non-AD series the problems were solved.

From what I can tell, the link you provided is intended to convert late model GM trucks with AD-230’s to 244’s, which are both computer regulated. …not so much for converting the 244 to older vehicles pre-ECM controlled alternators.

I am of the opinion that for the sake of the thread starters question, he is better off with a CS alternator even though the later model alternators are a high quality piece.

Interesting info. Makes sense.

[gchemist]

The AD-244 works great if you keep the RPMs down. It has no problems powering the LS1 fans and othe electrical components. For a nonperformance or daily driver, it will work great.
My problem is my foot.

[DirtyLarry]

I honestly don’t see how you will ever get an AD series to work properly on an older truck as there are internal differences with AD series alternator to work EPM system. Below is the Charging System Description and Operation from the service manual.


Electrical Power Management (EPM) Overview

The electrical power management (EPM) system is designed to monitor and control the charging system and send diagnostic messages to alert the driver of possible problems with the battery and generator. This EPM system primarily utilizes existing on-board computer capability to maximize the effectiveness of the generator, to manage the load, improve battery state-of-charge and life, and minimize the system's impact on fuel economy. The EPM system performs 3 functions:

• It monitors the battery voltage and estimates the battery condition.
• It takes corrective actions by boosting idle speeds, and adjusting the regulated voltage.
• It performs diagnostics and driver notification.

The battery condition is estimated during ignition-off and during ignition-on. During ignition-off the state-of-charge (SOC) of the battery is determined by measuring the open-circuit voltage. The SOC is a function of the acid concentration and the internal resistance of the battery, and is estimated by reading the battery open circuit voltage when the battery has been at rest for several hours.
The SOC can be used as a diagnostic tool to tell the customer or the dealer the condition of the battery. Throughout ignition-on, the algorithm continuously estimates SOC based on adjusted net amp hours, battery capacity, initial SOC, and temperature.

While running, the battery degree of discharge is primarily determined by a battery current sensor, which is integrated to obtain net amp hours.

In addition, the EPM function is designed to perform regulated voltage control (RVC) to improve battery SOC, battery life, and fuel economy. This is accomplished by using knowledge of the battery SOC and temperature to set the charging voltage to an optimum battery voltage level for recharging without detriment to battery life.
The Charging System Description and Operation is divided into 3 sections. The first section describes the charging system components and their integration into the EPM. The second section describes charging system operation. The third section describes the instrument panel cluster (IPC) operation of the charge indicator, driver information center (DIC) messages, and voltmeter operation.

Charging System Components

Generator
The generator is a serviceable component. If there is a diagnosed failure of the generator it must be replaced as an assembly. The engine drive belt drives the generator. When the rotor is spun it induces an alternating current (AC) into the stator windings. The AC voltage is then sent through a series of diodes for rectification. The rectified voltage has been converted into a direct current (DC) for use by the vehicles electrical system to maintain electrical loads and the battery charge. The voltage regulator integral to the generator controls the output of the generator. It is not serviceable. The voltage regulator controls the amount of current provided to the rotor. If the generator has field control circuit failure, the generator defaults to an output voltage of 13.8 volts.

Body Control Module (BCM)
The body control module (BCM) is a GMLAN device. It communicates with the engine control module (ECM) and the instrument panel cluster (IPC) for electrical power management (EPM) operation. The BCM determines the output of the generator and sends the information to the ECM for control of the generator field control circuit. It monitors the generator field duty cycle signal circuit information sent from the ECM for control of the generator. It monitors a battery current sensor, the battery positive voltage circuit, and estimated battery temperature to determine battery state of charge (SOC). The BCM sends idle boost requests to the ECM.

Battery Current Sensor
The battery current sensor is a serviceable component that is connected to the negative battery cable at the battery. The battery current sensor is a 3-wire hall effect current sensor. The battery current sensor monitors the battery current. It directly inputs to the BCM. It creates a 5 volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes.

Engine Control Module (ECM)
The ECM directly controls the generator field control circuit input to the generator. The ECM receives control decisions based on messages from the BCM. It monitors the generators generator field duty cycle signal circuit and sends the information to the BCM.

Instrument Panel Cluster (IPC)
The IPC provides a means of customer notification in case of a failure and a voltmeter. There are 2 means of notification, a charge indicator and the driver information center (DIC) SERVICE BATTERY CHARGING SYSTEM message.

Charging System Operation

The purpose of the charging system is to maintain the battery charge and vehicle loads. There are 6 modes of operation and they include:
• Battery Sulfation Mode
• Charge Mode
• Fuel Economy Mode
• Headlamp Mode
• Start Up Mode
• Voltage Reduction Mode

The engine control module (ECM) controls the generator through the generator turn on signal. It monitors the generator performance though the generator field duty cycle signal circuit. The signal is a 5 volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes. The following table shows the commanded duty cycle and output voltage of the generator:


Commanded Duty Cycle Generator Output Voltage
10% 11 V
20% 11.56 V
30% 12.12 V
40% 12.68 V
50% 13.25 V
60% 13.81 V
70% 14.37 V
80% 14.94 V
90% 15.5 V

The generator provides a feedback signal of the generator voltage output through the generator field duty cycle signal circuit to the ECM. This information is sent to the body control module (BCM). The signal is a 5 volt PWM signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-99 percent. Between 0-5 percent and 100 percent are for diagnostic purposes.

[ElGracho]

Originally Posted by DirtyLarry

I honestly don’t see how you will ever get an AD series to work properly on an older truck as there are internal differences with AD series alternator to work EPM system. ...


Generator
...If the generator has field control circuit failure, the generator defaults to an output voltage of 13.8 volts....

That's how. An old school (10-SI, 12-SI, CS-135) etc alternator has a voltage regulator with a fixed output voltage. They charge until the battery is at this voltage and the regulator tapers off the field current so the alternator doesn't continue to charge and boil or burst the battery. When the AD alternator goes into "limp-home" mode, it's acting just like one of the older series. It would work just fine like this forever, charge just fine and not hurt your truck or its electrical system. It's true you aren't using all of the features of the alternator, but its still a high-reliability, high-quality, high-amp alternator.

[gchemist]

I'm going to call
http://www.alternatorparts.com/ad_al...order_page.htm

They may have a solution to remove the drop out. A solution may be to default the output.

[DirtyLarry]

Yeah, let us know what you find out. The AD's are awesome alternators and would be a nice addition to our rigs.

[gchemist]

I talked to the alternator place where I bought it. They said bring it back. The can change the regulator out. The AD-244 will converted to a one wire alternator. All it will need is a wire to the battery. Yea, no more cutting out at high RPMs. I report back once it's modified and installed.

[keith61760]

Originally Posted by gchemist

I talked to the alternator place where I bought it. They said bring it back. The can change the regulator out. The AD-244 will converted to a one wire alternator. All it will need is a wire to the battery. Yea, no more cutting out at high RPMs. I report back once it's modified and installed.

Sweet. Hopfully it works better for you. May be the way to go when this one needs upgraded!