Can't seem to find the answer here:

What direction is the signal flow in the X9331 connector?

Meaning which side of the connector is from HU, and which side is to speakers?

 

The female side of the connector is coming from the HU. I just recently was splicing it apart and that's the side I worked with.

 

I just found this, that seems to be male from HU to female into connector.

Im now confused!!??????

 

Now you're making me second guess myself. I know I was working on the female side of the connector...and I spliced in my own amp (similar to what that connector you posted does)...but I could be wrong about the direction of flow....what I do know is that what I did worked...so I guess I should rescind my statement and suggest you go by what the picture suggests. I'm more likely to be wrong.

Good find! If I have time, I'll double check what I was doing and post my findings...

 

The female/socket side is signal from HU. Ignore that picture - it was just a quick (and not very good) picture for website. But it was taken of an initial production run from long ago where the input and output were transposed on the production drawings by the supplier.

Never expected anyone would be looking at it so closely....

 

OK cool.
My plan is to pop in the IA loom, (whenever stock is back) prior to plugging in the Alpine retrofit amp loom.
Send a low level signal to a powered sub.

 

This makes me feel a lot better! I was racking my brain pretty hard after looking at that picture wondering where I went wrong...and if it was wrong, how was it working...and so on...