4l80e
 

First off, this site is awesome. Ive been a lurker and you guys help alot. Hello. :D

Im replacing transmissions on my 91 C2500. They are both 4L80E but the "new" one I got has the older 12 pin style plug. My truck has the new style 11 pin plug. Can I just swap the newer style 11 pin internal connector into the "new" transmission I got? Will there be an extra part on "new" trans without a wire going to it since it originally came with 12?

Ive seen threads and suggestions when the truck has the older style pin and the trans has the new style pin. But its the other way around in my case LOL

I was just about to throw it on when I came accross this. :bang:

THANKS!

Welcome to the site. I'm sure your wiring loom was updated at one time or another because the earlier ones had issues with leaks. That would explain why you have the later loom. You can most certainly install the harness from your previous trans and you will be good to go. Hope this helps. Vince

Thanks for the reassurance Vince! I will be tackling it in a few minutes after some breakfast. I survived all day yesterday on a bowl of cereal lol