I'm swapping a b18c5 motor (01 uddm) into a 99 Civic HB w/ 99 Civic SIR wiring harness(I think usdm but no knock sensor plug). My alternator is a 01 type r with a 4 prong connector and alternator plug on my wiring harness is a 3 prong plug. So, my plug on the wiring harness doesn't have the green wire. So, I was wondering if it's possible to convert the 3 prong to a 4 prong and if so, how do you do it?

Thanks

 

Newbie here please help

 

Sounds like you have a Canadian SiR harness (all Candian 6th gen civics use a 3 wire alternator plug instead of the USDM 4 wire setup, IIRC its because the Canadian civics don't have an ELD) easiest thing to do in this situation is to reuse the original SiR alternator.

 

thanks for the help