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metal fan on the front, and another fan inside the housing at the rear. These alternators are rated at 85 to 105 amps in
stock form, can be rebuilt to put out 140 amps, and charge like a sumbitch at idle. They are all internal-regulator type;
apparently they assume you know that, because none of the books or catalogs tell you.
I know you don’t think the physical size is a big deal, but let Arthur Blackwell improve your mind: “the alternator is
much smaller physically and did not require dropping front suspension pieces to put in place.”
The CS130 alternators come with some interesting variations in main power connections. Some have a basic stud,
while others have a protruding rectangular block that a screw is run through crosswise. Whatever, it shouldn’t be
difficult to finagle a connection to the battery in the XJ-S.
The CS130 comes with a special regulator connector: a rectangular block with four pins in it -- one large one and three
smaller ones. The big one is the sense wire, similar to terminal 2 on the earlier GM alternators. You don’t need to
connect it to the main power connection three inches away because GM has thoughtfully done that for you internally.
Apparently, if you connect up a sense wire, it will override the internal sense connection. Hence, it is an optional sense
connector; you can connect it to the main bus for optimum performance, or you can just forget about it and it’ll work
fine.
The small pin right next to the big one goes to the ignition switch on cars without a dash indicator light. The middle
small one goes to a dash indicator light on cars so equipped. It’s not known what the farthest small pin is for, perhaps a
tach connector.
For clarity: you only need to connect up the main power cable and connect the middle small pin in the plug to the
existing NB wire in the XJ-S to get the CS130 alternator to work. If you get the plug with the alternator from a
junkyard, it’s probable the plug will only have that one wire!
If you don’t get a connector with the alternator, auto parts shops sell a variety of connectors to fit the CS130 regulator
socket. You will need to get one from somewhere -- generic spade terminals won’t work here. There are plugs
available with four wires, one to each pin. There are plugs with only three wires. There are adaptors (short harnesses
with a connector on each end) for retrofitting the CS130 into cars without dash indicator lights that originally had the
earlier alternators with 2-wire connectors. And there are adaptors for retrofitting the CS130 into cars with dash
indicator lights that originally had the earlier alternators with 2-wire connectors. Three out of these four will work on
the XJ-S (you won’t want the adapter for cars without dash indicator lights), so choose the cheapest one of the three. If
it’s the adapter you buy, just cut off the 2-wire connector and use the CS130 connector end.
If the CS130 in hand has the connections in an inconvenient position, the pulley can be removed with a 24mm socket
and an impact wrench, then the case separated by removing the three bolts using an E8 Torx socket. Then the front
case can be rotated to any of three positions and the bolts reinserted. Since the front case includes all the mounting
lugs, this effectively rotates the rest of the alternator, including all the terminals on the rear end, in 120º increments.
Note that GM alternators can be fitted with either a single-groove pulley or several different widths of multi-groove
pulley -- and of course most modern GM cars come with serpentine belts, so finding an alternator with a single-groove
pulley in the junkyard might be difficult. The pulley from the Lucas alternator will not fit. However, finding a single-
groove pulley for a GM alternator shouldn’t be too difficult or expensive, and they can be swapped out in a minute.
There are some reports that GM alternators all have problems with the rear bearing. SI units came with a needle
bearing, apparently a source of trouble. The CS130 comes with a ball bearing at the rear, a considerable improvement -
- except that they used too small a ball bearing. The CS130 has also developed a reputation for lack of durability,
apparently frying something in the electronics every 50K miles or so on the American cars they are fitted on. This
being an American product, there are aftermarket fixes: J. C. Whitney (page 691) offers a “Quick Start ‘Iceberg’”
rebuild kit, 81xx5780U, which provides improved rectifier cooling and a larger rear ball bearing for the CS130
alternator. If you are paying good money for a rebuilt alternator from a reputable shop, you may want to insist upon
such improvements at the outset.
J. C. Whitney also offers a kit, 81xx5781B, to convert the CS130 to 140 amp capacity. This is not necessary with a
stock XJ-S, but if you’ve added loads such as an electric radiator fan or a big sound system, it’s something to consider.