Click on thumbnail to
see larger picture.
|
|
In 1986 GM introduced the completely new, 105-amp, CS130 Delcotron alternator (CS130 = Charging System with 130mm diameter
stator) because the SI alternators could not keep up with the increased electrical demand and because overdrive
transmissions were lowering engine and alternator rpms. The CS130 weighs less, is smaller in diameter (but uses the same
6.6" mounting-hole, center-to-center distance photo 3), uses less
internal parts, has a better voltage regulator system, has increased durability and is less noisy (audibly and
electrically) than the SI alternator it replaced. There is also a 120-amp, CS144 version if you need more output because
you're running large amounts of electrical equipment in your vehicle such as high-powered stereos.
NOTE: This conversion is designed for cars with internally regulated alternators. If your car has an externally regulated
alternator you will need to convert it first. Use this diagram and go to Alex Bilan's Alternator Conversion webpage for more
information on converting to an internally regulated alternator.
You will need 105-amp CS130 alternator from and late-80's GM truck or full size car with mounting ears that are 180-deg
apart (photo 3). I got mine from the local PepBoys and it didn't take
too long to find one with the correct mounting ears. I paid about $100 for new one with a lifetime warranty. Most will
probably come with a pulley for a serpentine belt (like mine did) so you will have to change over your pulley if you are
still using a V-belt.
The flange for the tensioning bolt and the alternator bracket are tapped for metric bolts so you will need to get two 8mm
bolts with a thread pitch of 1.25mm. A 13mm wrench will be needed to tighten the bolts. The alternator bracket will also
need to be modified and you will need approx two washers to take up the space between the alternator bracket and the
alternator. Photo 11 shows the modifications needed to allow the bracket to fit the CS
alternator. The red line shows the original shape of the bracket and how much needs to be ground away.
Most of the connectors for the CS alternators are four wire but will only use two of them and the wiring is the same as
the SI.
- S = a heavy gauge wire to the battery supply (horn relay)
- F = not used
- L = a small gauge wire that comes from the idiot light and energizes the alternator
- P = not used
You need to purchase a conversion adapter that is just 2 short wires and 2 connectors. One is a CS connector to plug into
the alternator, the other is a female connector to accept the SI plug from your original harness. There are two different
types of conversion adapters. One is a non-resistor and the other has some resistance built-in it. The "L" wire that
energizes the alternator needs some resistance (35 ohms or more) in it otherwise it will cause the alternator to fail. If
you have a warning light in the dash then that bulb serves as the needed resistance and you should use the non-resistor
adapter. If you don't have that bulb or have less than 35 ohms resistance in the "L" wire then you will need the adapter
with resistance built in. If the "L" wire has more than 350 ohms then there is a problem with that wire and it will need
to be fixed.
Non-resistor adapters:
- AC Delco: 8077
- Haywire: 2110
- Painless Wiring: 30707
|
Resistor adapters:
- AC Delco: 8078
|
Steps:
- Turn key to run position verify charging system warning light comes on
- Remove negative battery cable
- Disconnect the 2-wire plug from the side of the SI alternator
- Disconnect the heavy battery wire from the BATT terminal on the back of the SI alternator
- Remove belt
- Remove SI alternator
- Install pulley from SI alternator to CS alternator
- Remove alternator mounting bracket from SI alternator
- Modify alternator mounting bracket (photo 11)
- Install alternator mounting bracket and 2 washers to the CS alternator
- Measure the resistance in the "L" wire
- Connect CS wiring adapter to the CS alternator
- Connect the heavy battery wire to the BATT terminal on the back of the CS alternator
- Connect the wiring adapter to the original SI connector
- Mount the CS alternator to the engine
- Install belt and tighten
- Check all of your connections
- Make sure alternator output terminal is not shorting to ground
- Connect the negative battery cable
- If you don't have an installed voltmeter, connect a voltmeter to the battery terminals
- Start the car
- The charging system warning light should go out and there should be 14v at the battery. If there is not, check all connections
NOTE: the alternator supply line that connects to the BATT post on the back of the alternator is usually a 10- or 12-gauge
wire. For a CS conversion, I suggest using at least an 8-ga charge wire.
|
