Im about to rip my hair out.

Just finished with a clutch install, started the car and noticed the battery and brake lights on. Proceeded to check connections and found everything tight. Scan tool reads 14.5v but volt meter on battery reads 15.3+. So I determined the voltage regulator must have gone belly up.

Pulled the alternator, it was a duracrap from the previous owner, this further solidified my theory. Put a new OEM alternator in, and same issue. Evoscan logs show 14.5-15v where they used to show 13.8ish.

I have checked to make make sure I didn't pinch a wire or something when installing the clutch, and I can't seem to find any other explanation after searching other than the alternator. I don't think it's likely that both alternators have the same issue.

any ideas are helpful and appreciated.

 

In case anyone else has an issue similar, my solution:

The "S" terminal wire (3rd one down when the connector is plugged in) seems to be the reference voltage for the ECU to determine regulation. My wire was outputting 3 volts lower than the actual battery voltage causing the ecu to compensate. I bypassed the wire directly to the battery and my problem was fixed. 14.2V charging. It must have been pulled or broken somewhere slightly. I didn't find any issues visually checking the wire.

 

You didnt forget the ground on the bellhousing?

 

No, I actually ran a new one, as well as the one on the intake manifold thinking they were the issue.

I replaced the wire exactly how it was, and it's fine now. So it was shorted somewhere.

 

Do you have any pic for which s terminal that you’re talking about because I have the same problem

 

Do you have any pic for which s terminal that you’re talking about because I have the same problem

 

he is just talking about the terminal that plugs into the alternator

 

so basically... you had a wire broke in your harness somewhere...

 

I bought a new battery harness from STM Just installed I and this is what’s happening to me