FD alt in S4 chassis, won't excite at startup
 

I have looked at the drawings again and again, here is how I am running it.

B - 12V through the stock connection. I put the S4 alt b post on the FD alt.
S - (White/Blue on FD plug) is run direct to battery. I know it should be fused but I want it to work first.
L - (White/Black on FD plug) is run to a Brown/Yellow wire.


My alternator plug had a Black/White wire and a Brown/Yellow wire. Everyone talks about the white/black black/white plug but I swear I don't have that plug.

I am running a haltech, most of the stock wiring to the engine has been replaced. The alt excites when I rev the engine (well, it did when before I rebuilt the engine) and I want to put this issue to rest.

Am I crazy and somehow wired into the wrong plug from the stock wiring? I have no other plug now and this is the same plug that ran my S4 alt....

disconnect and see if you get 12v at either of the small gauge wires with the key on, if not then there is your issue.

Looking at the engine diagram I have been a complete moron, I have the air bypass solenoid wire.

I found a cut white/black wire with red stripes as the third, this wire is 0v off and 12v at ACC/ON. Is this the wire I am looking for?

Based on the wiring diagram it looks correct, the white/black wire is the same source as the black/white wire just switched off a relay.

Ground the W/B wire and w/key to on it should force the idiot lights to light up. If it does then that's your wire.

I don't have idiot lights anymore, but I wired it in and it came alive when I started the car. Joy!

For the S, can I wire that into the black/white wire from the old plug? It looks like its on a +12 line or does it have to be +12V 100% of the time?

if you don't need an ammeter then don't worry about the other wire.

The old connectors black/white wire is not connected and my ammeter works fine. Then again I have no idea if its the correct black/white wire.

S terminal requires a constant voltage source.

Thanks, I will take the time to wire it up correctly and it should put this whole issue to bed.

Both satch and karack, thank you much.