Alternators, Models & Design, Part 4, Delco CS130

The Delco CS130 Alternator was the first of the Delco units that started to be designed for the engine compartment instead of being universal.  It came out in the late 1980's about when the cars went from a squared look to a more rounded aero-dynamic look.  They generally came in three amp ranges, 85, 100 and 105 amps, with the 100 and 105 amp units the most common.

Most all the units used the serpentine multi-groove drive belts, but can use the standard 'V' belt also.  After these alternators had been out in the field for a few years, they came out with heavier bearing units, as the bearings in the standard units were failing in rougher service.  There were several different drive end (front) housings used on this unit depending on the application, which made it quite difficult to substitute with a salvage unit.  The picture below is just a few examples.  Notice the two housings in the lower row in the center and on the right have heavier bearing bosses as compared to the other housings.

There were also a couple of differences in the bearing hole in the back housing as one used a corrigated metal strip to support the bearing while the other used a black plastic ring.  The plastic ring housing was the later version and it supported a heavier wider rear bearing and was used whether it had a heavy front bearing or not!

Internally, almost all the parts are interchangeable, that is they will fit most all the units, 'BUT' may not be correct or even function in the application.  For this reason, you must find the correct unit for the correct make, model and engine size.

The biggest difference is in the regulators.  Most of the regulators all look identical, but their internal circuitry were all different.  They all had the same four terminal plug in set, with one large terminal and three small terminals.  Besides other circuitry differences, the two main terminal designations were P-L-I-S which was an ignition controlled unit and P-L-F-S which was a computer controlled unit.  More recently the aftermarket has come out with a 'one wire' regulator for these units, which now makes this unit more versatile.

The main reason that about 90% of these units failed was the rectifier.  That component took and produced most of the heat in the unit and the OE diodes would only last so many cycles before they gave up.  Fortunately aftermarket heavy duty rectifiers were produced in the early 2000's, that made these units more reliable.  In fact, these rectifiers are so reliable, that I have never had a failure on any of them that I have installed, NEVER!