Converting to a serpentine bracket from a late 80's F body meant a SI to CS alternator swap. Not being familiar with the CS130 wiring made this a bit more complicated. The complication was increased due to a previous warning light to gauge swap that rendered the brown trigger wire useless. The SI alternator must not use the brown wire as a trigger as I drove for a couple years with the wire being a dead lead.
My research found that the only necessary wires on the CS130 are the brown trigger wire and the rear lug to the battery. The junkyard cars had variously a red wire from the S terminal , a brown white stripe wire from F terminal and always a brown wire from the L terminal.
I also found reference's to a Delco or Echlin SI to CS adapter plug. There are two item numbers depending on whether the brown wire goes through a dummy light.
My first try was a failure resulting in a burned up voltage regulator. When I checked the voltage on my brown lead from the gauge cluster, I found it was dead. The CS130 needs a 12 volt switched lead with at least 50 ohms resistance through it. In most cars, this is accomplished by the dummy light. The lead power wire to the alternator was also really too small for this high amp alternator.
I went back to the drawing board and this time I bought a junkyard CS130 along with the lead wire and the plug. The Echlin plug adapter I bought was supposed to have a resistor wire built into the yellow wire that hooks up to the L terminal. It did not and as such fried the voltage regulator. Radio Shack has a nice 50 ohm resistor that sells for about three dollars.
The S wire is not absolutely necessary but does serve an important function of telling the voltage regulator what's in the system as opposed to relaying on what the alternator is producing. I didn't figure out the exact function of the F terminal. On the 1993 Caprice wiring diagram, it appears to go straight to another 12 volt source.
The wiring I cooked up was first to tie the brown trigger wire into the EGR solenoid power wire. It only has a load for a few minutes at best, so it seemed like a good enough switched source. Since the Echlin harness lacked the needed resistance, I cut the 50 ohm resistor into this wire.
A new S terminal wire was run to a junction bus that is between the battery and the ignition timing box. The 6 gauge wire that I grabbed was patched into the battery cable to the alternator power lug.
Another way to say it is that the Echlin plug has a S and a L terminal. The wires are yellow and red. The other end inserts into the SI alternator plug. The colors are now brown and red. If your brown wire has 12 volts and goes through an idiot light, you're done. If not, you need to add a resistor. An example is if the brown wire comes straight off the ignition key or through a gauge, there must be a resistor. The SI red wire went to the power lug on the alternator. It's a waste of wire to hook it up like this on the CS. Either leave the red wire off or run it to the battery so the regulator can compare battery and alternator voltage.
I had $30 in the junkyard CS130, $20 in the Echlin adapter harness and $3 in the radio shack resistor. Since the resistor was a 2 pack, I took the extra one and cut it into the original CS plug and sold it on eBay for $10.
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