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Supercharge Your Alternator

P69550 Image Large
David Kennedy
| Contributor
Posted April 1, 2001

140-amp GM Alternator Upgrade

Step By Step

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  • Disassemble the alternator, taking care to note the position of any spacers behind the pulley or bearings. The Iceberg kit’s instructions have no photos, so take your time to note how everything fits together. You will reuse the front half of the alternator case, the rotor, the voltage regulator, a plastic dust shield, the fan, the pulley, and the seven bolts that hold everything together. Clean up these parts, and ditch the rest.

  • The rotor from your core alternator has to be good for the alternator to work. Here a multi-meter is used to test the continuity of the windings of wire that wrap around the rotor. Touch the test leads as shown to the two points on the rotor and you should have a complete circuit. These two points are where the brushes make contact with the rotor, so they may need to be cleaned up with a piece of fine sandpaper.

  • The Iceberg kit not only increases the power output of the alternator but also cools the new rectifier supplied in the kit 400 percent better than a stock alternator housing would. A copper heat transfer compound is applied to the back of the rectifier to ensure as much heat as possible is transmitted to the outer housing.

  • Here the two halves of the alternator case can be seen. The new rear housing on the left is part of the Iceberg kit. Except for the voltage regulator, all of the electrical parts and both bearings are replaced.

  • The alternator is reassembled and the three wires from the kit’s high-output stator are soldered to the rectifier. Do your very best soldering, as a poor-quality connection here will decrease the output of your new unit. In this photo you can see the Iceberg kit’s heat sinks that pull all the unwanted heat from your new powerplant. With it all back together, reinstall the alternator in your rig and pat yourself on the back.

Want more power? National Quick Start has got just the thing for those of you who are running an ’87-’94 Delco-Remy CS-130 GM alternator. GM rated these alternators at 85-105 amps depending on the application. Now for about $100 you can upgrade your original alternator to 140 amps of battery charging power with National Quick Start’s Iceberg upgrade kit. We found a junkyard core with a good rotor and voltage regulator and rebuilt the alternator on our workbench for about the same price we would have paid for a rebuilt 105-amp unit from the parts store. We’ll never buy one of those rebuilt units again now that all the voodoo that once surrounded these little powerplants has been brushed away. Our core was from a ’90 diesel K3500 that was originally rated at 100 amps. With the Iceberg kit installed, the same alternator put out a peak of 138 amps at 14.6 volts when loaded down with our ARBST test equipment.


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Akron, OH
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La Salle, IL