This is for those of you who have dual alternators and wanted to switch to just a single alternator setup for whatever reason. It took me a LONG time of searching to find the information needed to complete what would seem to be a simple task of remove and call it good. However that isn't the case with these trucks and in a second you will see why.
Not sure how many knew this but my truck originally had dual alternators from the factory. Now the way the ECM is setup it randomly selects which alternator to use to charge the system each time the truck is started. That means you CANNOT simply unplug the second alternator and go on, because should you do that and the ECM selects the alternator that is no longer there, the truck will drain the batteries and leave you stranded.
All that said there is a simple work around.
On the passenger side fender well there is a harness that the factory dual alternator plugs into. When you remove the second ALT the harness needs to come out too.
It plugs in right here.
Those of you who don't have a second ALT will see a little "loop back plug" in the end of the harness. This is what you need to replicate with the factory dual ALT harness.
It's very simple.
Remove the old harness and find the plug that looks like this.
I had already modified this one before I took this pic. But the green loop back is what you need to worry about. You have to change the pin out locations for the green wire and remove the others.
To do that you need to take and pull the rubber stop out so you can access the release pin.
I used a piece of 1/16" tungsten to push it out.
Once you have removed the red tab, proceed to remove the other wires and pins and put the two green pins in the location you see here, then button it back up and plug it into the factory harness along the fender well and you are DONE.
I only had to do this because I have decided to use fire hoses for injectors and needed a twin pump setup and the way they mount to the head you can't utilize a dual ALT.
