[Diy_efi] CS Failure

[David Allen]

  Have you measured the alternator output current with an "amp-clamp" meter?
It would be good to get an idea of the load on the alternator immediately
after cranking, after running all day, and running with all the electrical
accessories on. What is the alternator rating?
  These CS 130 alternators are failure prone due to overheating rectifiers.
This caused by overloading or air restriction of the rectifier cooling fins.
  By the way, are you sure the exciter is connected correctly?  According to
the manual I have, the 1-wire exciter with indicator light should be
connected to the "L" terminal. With no light, the "I" terminal.  Terminal
"F" is a load indicator terminal for the alternator.
  Could you have the wrong voltage regulator for your application?  I don't
know what happens if an external voltage is placed on the "F" terminal.
Maybe it could overfield the alternator and make it overcharge.

CS alternator pinout. There are 2 versions that I know of:.

First,
P - A/C pulse tap. (Diesel tachometer signal output)
L - Indicator Lamp. Also this is the 1-wire exciter connection.
F - Field voltage.  This is a diagnostic terminal used to measure field
voltage. On certain cars, the ECM uses this to determine how much of a
mechanical load the alternator is presenting to the engine.
S - Voltage Sense. Optional input to make the alternator regulate voltage
based on a remote sensing point.

Second,
P - A/C pulse tap. (Diesel tachometer signal output)
L - Indicator Lamp. Also this is the 1-wire exciter connection.
I - Ignition Input. This is a 1-wire exciter input for use without an
indicator light. There is a resistance in the alternator between this
terminal and the "L" terminal.
S - Voltage Sense. Optional input to make the alternator regulate voltage
based on a remote sensing point.

Look at the regulator its self, not the harness plug.  If the regulator is
marked "F" where your exciter wire is connected this is not right.
Good luck,
David



----- Original Message ----- 
From: Clayton Martiniuk
To: A list for Do-It-Yourself EFI
Sent: Saturday, November 26, 2005 4:40 PM
Subject: [Diy_efi] CS Failure


Hello, I have an 1994 Chevy 350 that Keeps eating alternators for some
reason. They seem to work for about two days and then shit out. I have a cs
series alternator powered with one exciter/indicator wire at the F terminal.
Looking at the indicator bulb, I'll start the truck, the light will go off
for a while but turn back on intermittently. I heard that these years of
trucks seem to have a problem. Some say to ground the back of the case to
the batt but I dont see how on mine. I am probably close to duty cycle but
no major power drains. It gets very cold here around -20 to -50. I am
running an electric fuel pump. I am running an red top optima with 800 cca.
Does this Battery require special needs? Is the answer an larger amperage
generator or am I doing something wrong?
I am sick of buying alternators and no one can seem to figure out whats
happening.
                                                Thank you for your time
                                Clayton Martiniuk



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