Ignition & Electrical / Q&A

Ask Away! with Jeff Smith: How to Connect a GM CS-130D Style Alternator in Place of an Original CS130

I have been looking for how to wire a CS-130D alternator in place of my CS-130. I came across your article on how to hook up a new alternator in place of the old one. But the article ended before I got a full answer. I have a 1993 Corvette that I am swapping in an LQ4 truck engine.

Since the wires on the new plug are far too small to conduct the output I assume it is handled by the main power lead (large red cable on the back of the alternator). That leaves the four small wires on the plug. They are blue, green, yellow and white. Also the plug has no markings on it. Can you give me a direction to go on this? Thanks.

B.J.

B.J.

The story that this reader is referencing is a piece I did for an online publication. The story outlined the different types of plug-in connectors used by GM. Essentially there are four different types of alternators dating back to the first ones used by GM in 1962. But we’ll focus here on the difference between the last two versions. The CS-130 appeared in the mid 1980s. This alternator is actually a great update for earlier GM alternators.

In B.J.’s case, he needs to update from the CS-130 to the CS-130D version which was used in most Gen. III LS engines. The CS-130D uses a different four-wire plug-in connector.

His first question concerns the output connection which is actually the large post terminal with a stud and nut arrangement. This is where the power is sent from the alternator and should be connected with a 6 or 8 AWG large diameter power lead from this terminal directly to the positive post on the battery. Using a large diameter wire allows the alternator to deliver its maximum current to the car’s electrical system. Most stock CS-130D alternators were 105 amp models with some trucks and other vehicles equipped with 145 amp versions.

Addressing his next question, the connector for the CS-130D is slightly different than the CS-130. Each of these wires should be labeled, if not on the connector itself then directly on the alternator. The accompanying illustrations should help you with the conversion. For the CS-130D, there are four connections labeled ”S”, “I”, “L” and “P.”

In your case, Powermaster makes an adapter harness that offers a direct plug-in into the CS130D alternator with the other end the proper connector to accept the original 1993 Corvette alternator wiring harness. This makes the update to the later model alternator extremely easy. That connector is part number is PWM-161.

But let’s also help those readers who may be interested in an LS swap into a 1960s or 1970s GM car like a Camaro, Chevelle, Nova, or pickup and want to use the CS-130D alternator. In this case, the easiest step is to use a generic connector to plug into the CS-130D alternator. We found a connector pigtail in the Standard Products line under part number HP4695 with four white wires exiting the plug.

To convert this alternator for use in an early GM car, there are only two connections that need to be made. The “I” terminal would be connected to switched ignition under the dash. The second connector would be the “L” for a charging warning light on the dash. If you choose to not use a warning light, it’s best to connect a 50 ohm resistor into this circuit connected to a switched ignition source to allow the alternator to function properly. We’ve been told that if the resistor is not used, this will eventually burn up the internal voltage regulator, so it’s best to use the warning light circuit or at least the proper resistor.

This will allow the use of this high output alternator with most all LS engine swaps and all will be right with the world.

At least as far as your charging system is concerned.

The connector on the left is a square type connector for the earlier CS130 style alternators. The connector on the right uses radiused corners and is intended for the CS-130D model alternator s used on LS engines. (Image/Jeff Smith)
This is a generic four wire, CS130D pigtail that has four white wires. The only two that are required are the ones for the “I” and “L” connectors. This connector is a Standard Ignition Products piece available under part number SMP-HP4695. (Image/Standard Motor Products)
This illustration shows the position of the four wires and their labels. The I and L positions are clearly marked in reference to the clip. (image/Jeff Smith)

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2 Comments

  1. Pingback: How to Connect a GM CS-130D Style Alternator in Place of an Original CS130 – Lansing Supports

  2. Ronnie Moore says:

    Thanks for all the helpful information. You never know when these tips will come in handy for yourself or helping you gear head buddies.

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