i have a charging problem

my alt is putting out 12.5volts no matter the rpm


i have a s300 p28 ecu and a obd1 3 wire alternator, (green round connector with a factory plug in the 4th pin hole)
i think the engine harness came out of a edm or uk market civic

i asked my homie to see what vehicle the harness came from

my engine is a d16z6
and i have a yellow top group 34 battery

anyways

the wiring
tested everything with the key on engine off
and disconnected the alt plug

a blue wire, has no power to it
white/green wire, 12v
black/white or maybe yellow 12v to it

im not sure what the blue wire is for

any clues as to why my alt isn't working?

 

engine side of the harness came for a D15z3

that doesn't use a ELD

after work today, im gonna see what pin those 3 wires plug into and then I can start to figure out the problem

 

took the harness apart at lunch and it seems like im on to something

the blue wire wasn't connected to anything

the white/green is connected to A16
and black/yellow has ign 12v to it
i think its connected to drivers side 303 plug #3, will check when i get home from work, forgot to write it down at lunch time

i think this is how the wiring should be

black/yellow Ign
white/blue dash light
white green A16
blue D9

i dont think i need a dash light for it to work

 

I think the alt is done for

I wired in the 4th wire, white/yellow, gave it 12v
black/yellow 12v
white blue to light is working fine
blue has 4.6volts, d9

alt wont put anything out
so im gonna pull it and take it to get tested and maybe rebuilt if it will be cheaper then replacing

time to look up rockauto and autozone