I need advice on this. Since my alternator quit working I decided I should upgrade to a 124 amp alternator from a 100 amp one, silly me I thought it would bolt right in. I see GM uses a different pigtail for this alternator (why would they make simple difficult) and the backing plate doesn't line up with the bolt hole on the back of the new alternator.

• Is there a short wiring harness I can get to replace the one that goes from the alternator to just over the valve cover, or will I need to fabricate one?
• Is the bracing / bracket on the back side of the alternator necessary (I assume it helps stop the alternator from vibrating)?
• Do I need to replace anything else to ensure reliability down the road?

1997 GMC 2500 6.5 Turbo Diesel Pickup

 

Depending on where you bought your alt from they should sell a pigtail, you will need to cut and splice the wires for the new connector on the back of the alt, there should be letters by the pins on the alt defining what each pin does, I haven't seen a bracket on the back of our alts before, I have same year as you do.

 

Thanks,

NAPA did have the connector, although I did have to look up the part number myself (the guy at the counter was useless):

• Line code UNI
• Part number EC101

I was hoping not to splice, although I will solder the connection and put heat shrink tubing over it. Living on the 'Wet Coast' I've learned that splices often come back to haunt you once moisture gets in and works at corroding it for a few years.