Whether it is the alternator that should be a good performer or must be a simpler placement, there are different Chevy alternators available in the market. These are the alternators that are originally used by the GM. The 3 wire OEM styling is best for the replacement. The 1 wire can be the ideal selection to clean the whole setup and easily perform the installation. Before purchasing the right alternator, it is important to understand different types well.
Externally Regulated Diagram
This type of alternator is quite old style. They are also called the 2 or 3 and sometimes even 4 wire alternators. Irrespective of the name, the primary difference is such alternators work with the external regulator. In the mid-’60s when the generators were getting phased out, it was then such type of alternator that was used as the after generators.
3 Wire Alternator
Another type of alternator that is worth considering is the OEM style. This is also popularly known as the 3-wire alternator which can be regulated internally. It comes with a charge post and has two terminals that can be seen from the back. Usually, the terminal on the left side is known for the exacter or some even called the field circuit. The terminal which is on the right side can help in sensing the circuit. It can be quite complex when the wiring needs to be done. However, the benefit of charging at a low rpm is quite good.
1 Wire Alternator
Talking about the 1 wire alternator, this is one of the best options to save time on installation. It can be set up without any mess. There is one wire in this alternator that connects the terminal of the charge directly with the 12V source or the battery. It is often regulated internally and is usually grounded using the block. Such an alternator does not have a hook-up kind of light to warn. However, there are so many custom applications that work the best with the Voltage Gauge in place. When it comes to speed cut, well it can be quite high around 12000rpm or even more than that as compared to another alternator. This means that it will not charge if it is idle. The only exception for such an alternator is the 140amp performing Tuff stuff 1 wire alternator which has been rated at750rpm charge.
It is quite easy to know which are the Chevy alternators that will be used. These two vertical terminals should be used in which the connector has to be plugged in. On the GM vehicles in 1969-1988 only SI alternators were used. The common models 12SI and 10SI alternators were used on vehicles that ran between 1975-1985. It is even possible to use the two key identification points of such an alternator. This works as an external fan with the 2-charge indicator light terminal and even the pulley of the V belt that can be found on the alternator backside.