This shows you a side by side comparison of the new and old alternators.  The bolt holes are in the exact same places.  I had to ream out the bottom hole of my new alternator very slightly to allow me to reuse my old bolt.

This is a view of the back of both alternators.  The rectifier bolt is where the yellow wire and the new 8 gauge wire will connect to.  The stator plug will be wired to the white wire from the regulator plug.

This shows what the wiring harness looks like after pulling it out of the truck.  The plugs on the right goes to the alternator and the plug and ring terminal on the left goes to the starter solenoid.  The wrapping needs to be taken off to be able to get at the wires inside.

Now you can make the necessary modifications to the harness.  First, cut off the white and yellow wires about 12 inches from the regulator plug and remove the plug with the two black wires.  Next, connect your new stator plug to the white wire using solder and heat shrink tubing.  Then attach a ring terminal to the end of the yellow wire and solder.  Finally, cut the new 8 gauge wire to the right length and attach and solder on ring terminals on both ends.  One end of the 8 gauge wire will attach to the rectifier bolt on the alternator and the other end will attach to the starter solenoid.

Now you can install the new alternator using the new 2" bolt on the upper mount.  Once the alternator is in place, plug the regulator plug in and connect the yellow wire and one end of the 8 gauge wire to the rectifier bolt.  Plug in the stator plug and attach the other end of the 8 gauge wire to the starter solenoid.  Finally, reconnect the green wire with the plug and wrap everything in 1/2" wire loom and make sure everything is secure.  Once all the wiring is done, you can put the serpentine belt back on and reconnect the battery.

Now you can test the alternator.  Before I did my alternator swap, I tested my old alternator.  The battery was at 12.74 volts with the engine off.  Then I turned on the engine and it was at 14.57 volts with all accessories off.  Next, I turned on all the lights and my heater and it was at 12.37 volts and dropping.  Clearly my old alternator couldn't keep up.  After installing the 130 amp alternator, it tested at 14.67 volts at idle with no accessories on.  Then I tested it with all my accessories on and it was at 14.47 volts.  I am impressed with only a 0.2 volt drop and anyone who has a problem with their alternator not keeping up should consider this swap.

Off Road T rucks

Page last updated on October 18th, 1999