CS130 to CS 130D alt conversion - Third Generation F-Body Message Boards

Danno · 01-16-2004, 08:42 AM

After reading many posts about the low charging curve of the stock CS 130 alt I decided to do some research on the subject. Later GM cars with the "D" version do not suffer from the same problems,i.e. tach bouncing with turn signals with high accessory load especially when running the rear window defroster. The project started when I had to change the alt in my daughters 98 Cavalier. Since I had little experience with the newer D version I decided if they could be retrofitted into my 89 IROC. I did the 140 amp upgrade and essentially wound up with the same problem I read about here. I kept the core from the Cavalier, and found that the problem was and open diode, the alt would charge when cold but would turn off after 15 min or do of driving. The CS 130D uses a newer design regulator referred to as a "asvr" or application specific regulator. Many of the newer regulators are driven by the PCM for more precise control of charging based on engine load etc. The Cavalier used 5 volts and 2.5-2.8 voltages at the plug for control, not desireable for the 12 volts I had to work with. I found on the Transpo web site the correct regulator, a D702 thier number. It only requires a single wire at the plug to activate it, same setup as my 97 Blazer. Physically the "D" will fit right in to a standard 130 mounting, the only difference is that it was clocked different, the rear support was 180 out. That is where the fun is if you attempt it, unlike the 130 the "D" has the stator pressed into the front housing. The beauty of the electronics of the "D" is that all electrical parts, rectifier, regulaor and bushes are accessible by simply popping off the rear cover. I made a jig to press out the stator if you do this I would recommend using an alt shop. They will do it for a nominal fee. After it was reclocked I used a NAPA AC92 rectifier, the new regulator and brushes. Parts ran about $75 total including a new plug for the "D"-it is different from the standard 130. Delco PT 1136 is the plug kit, $16.41 online. I used the old pulley and spacer from the camaro, it eliminates the outboard fan, the "D" has 2 internal fans. The other tricky part is the rear support, I elongated the top hole that attaches to the alt and had to open up the bottom one and use a washer/lockwasher setup. Cut off the old plug attach the new one using the brown or tan wire-eliminate the red one. The socket on the "D" will be marked with letters-use the "L" terminal. Insert a 560 ohm 1/2 watt resistor in series with the brown/tan wire and cover it with heatshrink. The asvr reg's need very little current to turn them on. You will need a different rear lug to the batt also. End result, with full load all low power problems have been eliminated and it's a much more reliable unit especially where heat is concerned. And thats with a 105 amp stator. Want more info, PM me and i'll be glad to answer any questions. Moderator, feel free to place this elsewhere if it's inappropriate for here. Dan. You will need a soldering gun, impact driver for removing the pulleys and 60/40 solder and small wire cutters. The new plug kit comes with 4 wires and four butt connectors. You can cut off at the plug all but the "L" connection. Covering the splices and unused red wire with black split conduit makes for a factory looking job.