I know this is an older post, but as I was searching the site this post seems to best match my situation.
I have a 2004.5 2500 and I installed a 220A alternator from a fourth gen this weekend. I changed the terminal block from fourth gen to third gen (thank you @KMech
) so the factory wiring would stay intact.
The alternator to battery oem connection was in really bad shape, so I made up a new one using #2 wire. All connections at the passenger side positive terminal were cleaned and reconnected. The plug that connects the harness to the alternator field will also be replaced soon as it is in rough shape.
Once running, the alternator is charging right at 15 VDC. This is measured at both batteries with a Fluke 87. The voltage has never been this high ever before and I am concerned. I drove the truck for an hour taking voltage measurement with the DMM along the way and it remained steady at 15 VDC. I will add that the temperature has been in the low 20ís as Iím going through all this.
I removed the 220A alternator and took it and the 136A alternator to the local parts store to be tested. They both passed all tests. I reinstalled the 136A alternator and nothing changed: the truck is still charging at 15 VDC.
The only things that changed is that some connections were cleaned, a new alternator to battery cable was installed, and the plug that controls the alternator field was disconnected and reconnected a few times.
Has anyone had this issue? Is it possible the field connection was less than ideal before I cleaned everything up and now itís where it should have always been? Can the max charge voltage be dialed back with a programmer?
Thank you all for your time.
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