I have a 99 Si, converted to OBD1. I just recently converted from a Kenji Chipped P28 to a Hondata s200. The car ran fine on the P28 and VAFC and the voltage always stayed above 13.5 volts while the car was running. After changing over to the s200, the voltage will fluctuate a lot. When cold, the car will be at 14 volts at idle, but once it warms up, it will drop to close to 12.0-12.2 under 3000 rpms. Its very strange, its extremely noticable when the headlights are on. The lights will dim under 3000 rpms unless the car is decelling with the clutch out. This also happened when I put a stock P72 ECU in my car as well. Has anyone ever seen or had this happen? It never did this with my chipped ecu, which is very odd. I don't have problems starting the car either. The Battery light does not come on either. Any comments?

 

Nevermind, figured it out