Need some wiring help.

[Nismo1182]

On the fuse box by the battery tray, you know how theres 3 plugs facing the motor and one plug hidden on the back. Whats that hidden plug for? When I did my swap, the 3 plugs went in fine but there was no plug to connect to that hidden one on the back.

I thought it might be for one of the transmission sensors, then my alternator went dead. So I bought a new one and the new one isnt working either.

So ive come to 2 conclusions:

1. The new alternator was bad to begin with.2. That hidden plug has something to do with the alternator.

I just need some verification on that plug before I take off the alternator again

[SpeedRacer1]

What engine and chassis are we talking about here?S13 SR> S13S13 SR>S14S14 SR>S13S14 SR>S14

[Nismo1182]

Opps sorry, its a CA18DET into a 90 S13. The wiring is the exact same as a SR wiring job. But anyway, its the lower harness im talking about (Alternator, Starter, transmission) You know how they all come up and plug into the fuse box by the battery. Well one plug is missing.

[SpeedRacer1]

Alright, I might have time later to take a look at my wiring but im not sure. I noticed you already posted in the CA18DET forum, good start .