For a wiring diagram on B&C Models, go down to the boxes on the left, click on tractorlinks.com, then click on Allis Chalmers, then click on AC Model B Resto site of Herb Blair. Rifle down and on the left in Herb's site, you'll see "wiring diagram". Click on that and there ya go! One wiring diagram for B&C Models. For serial numbers, go into the Unofficial Allis Website and you can find out what year your AC is by using their serial number chart. If you need help with any of the wiring, or electrical parts for your C, drop me a line, I'd be happy to help you out. Good Luck! Have fun!