As I was really looking for better charging at idle than the original 10DN could deliver, I finally got around to installing the CS130D alternator I got from Carl last year. The CS130D is able to deliver 100 amps at idle.
While a 10 or 12SI internally regulated alternator would be a good choice as well, I think the CS130D is superior.
A easy retrofit perfectly suited for our old GM's.
Dimensions;
The bolt hole faces relative to the front are set very close to same plane as the old alternator. Perhaps 1/8" more forward and perhaps 1/4" shorter in spacing between. The CS is actually a little smaller in length.
The top and bottom holes on this model of CS are offset from the pully shaft unlike the DN which are inline with the shaft. I think some CS models are inline, however this style will require a slightly longer belt as to not bottom the upper bolt in the bracket slot.
This model of CS is clocked similar to the DN in that the plug is close to the same spot. All the old wiring reaches the new with room to spare.
Any further retrofit to a next gen (CS144) would require a bunch of modification to fit our old motors, as it is physically MUCH bigger. The CS130D is pretty much as far as you can go here.
Belt;
Stock uses the Dayco 15445 belt. 44.5" long. Replaced with the Dayco 15470, 47.0" long
Pulley;
The pulley off the old DN alternator is a direct bolt on to the CS. Same shaft diameter, same nut. When secured, it sits close to same plane relative to the new top and bottom bolt hole faces. 1 7/16" give or take. So no spacers required and the belt will line up.
Bracket;
The one little hitch here is the distance between the top and bottom mount is about 1/4 shorter on the CS. Was able to modify the upper bracket to allow it to drop down to meet the upper mount hole.
Cut and welded the slot end to be further down the bracket, and have it clear the Alt at the far end. The design of the bracket is such that it will drop the slot down if required. Loosen the T Stat and WP bolt and it will move down.
It's likely you could have a 100% bolt in by choosing a different case configuration. I'm still trying to find a comparison diagram.
Original Bottom and forward bracket off the WP works the same with the CS.
Spacers;
Cut two pieces of scrap pipe to act as spacers in the bottom bracket.
5/8" OD
Rear 1 5/8", center 2 1/8".
Blackpipe (Gas/air) will work here as well.
The DN configuration,
Bolts;
Uses the original bottom bolt, requires a 9/16 through bolt up top as the case is not threaded to accept a bolt. Would be metric if it were.
Has 2 12mm threaded bolt holes on the back. Used one to attach a ground wire.
Output stud is bigger than the DN. 12mm.
Wiring;
Purchase a CS 130 "D" type plug. The cheap amazon 4 pin weatherpack plug (red, below) will also work here, it's a near perfect copy of the same plug. Cut the old harness and splice in as shown below. Couldn't be easier.
Note: you must run the old idiot light feed or a wire with a ???ohm in line resistor to terminal "L". Running full battery voltage to this input will quickly destroy the rectifier in the new alternator. This cannot be overlooked.
Ran a beefy ground wire off the case directly to the battery negative terminal just to be sure.
Hooked it all up, pre test, the ALT lamp lights with the key in the on position. Good. Start, light goes out, seeing 14.8 volts initially, then drops to 14.2.
Comes off high idle and stays at 14.2.
Took if for a drive, headlights on, heater blower full, seeing a 13.4-8 constant. Pulled in the drive, high beams, wiper, blower motor full and radio on...still at 13.4 at idle. Excellent! Seems to even run better, and man does that top come up and down fast now!
I'm happy so far. I can now enjoy bright headlights at low RPM's. No more yellow! By by little weak 10DN, served well, but you'll not be missed.
