# Can someone double-check my HU wiring (STI content)



## Hostile (Nov 18, 2001)

I am installing a Pioneer AVH-X4700BS with the following additional components into my 2015 STI:

SVXdc's 20-pin Forward Harness
SVXdc's Axxess SWC-1
MicroBypass

Pioneer's wiring diagram doesn't have pinouts and is a bit difficult to read and I was hoping someone would be willing to double-check my wiring pairings

How I have them paired up:









SVXdc's 20-pin Forward Harness Install and ASWC install guide

Here are the instructions from the Pioneer manual:

















Here are the instructions for the MicroBypass if anyone is not familiar with them:









I think I have it all correct but I only do this every 10 years or so and I'd love to have some more eyes on it before I start cutting/stripping/crimping.

If anything is unclear please let me know.

thanks!


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## JaxACR (Dec 6, 2007)

Looks like you've got it pretty well covered. The only thing I'd recommend changing is the amplified antenna wire in the 20 pin harness to either the blue/white in the Pioneer harness, or preferably to solid blue in the Pioneer harness if it has one. Connecting it to red will have the antenna amplifier powered up any time the car is in accessory or run, blue/white will have it powered only when the head unit is powered on, and blue (if the Pioneer harness has it) will power it only when you are on AM or FM. Functionally you probably won't notice a difference in any of the above, it's just a more "correct" way of doing it.

All of your grounds, as well as the brown/black from the ASWC-1, can be tied together at one point. If you're using crimp caps, just twist all five wires together and crimp. If you're soldering or using butt connectors, twist the grounds from the Pioneer, ASWC-1, bypass, and the brown/black all together and connect to the ground in the 20 pin. Sorry if I'm telling you something you already know, just trying to help you keep it tidy.


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## Hostile (Nov 18, 2001)

Thanks for the reply Jax. I needed the blue amp wire from the HU for the blue wire on the bypass and it specifically says to not connect the bypass to a powered antenna lead. That's why I put it on the switched +12. I double-checked with the guy who made my harness and he said it'll be fine. 

Pic of the harness all done up:









All connections are heat-shrink butt connectors except for two for the bypass. The wires on the bypass were a tad small for the butt connectors so I used closed-end connectors two of them. The third wire (ground) was combined with another ground so I was able to use a butt for that connection.

Any electrical tape you see is for either wire management, to keep bundles together and smaller, or in some cases I had to cover a couple butt connectors because my crimpers are new and they punctured the plastic so a little metal underneath was slightly exposed.

All in all, not bad for my first non-standard harness if I do say so myself.


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## JaxACR (Dec 6, 2007)

Looks good, nice clean harness!

Just to clarify, does the Pioneer harness have a blue and a blue/white wire? Or just blue/white? You're absolutely right, the blue wire from the bypass should be connected to the amp turn on from the Pioneer (blue/white.) Solid blue, if your Pioneer harness has it, is for the power antenna. You can connect the bypass to blue/white and the antenna amplifier in the 20 pin to blue if present, or if not they can both be connected to blue/white. Either way, the antenna will still work fine connected to the red switched 12v wire, it'll just keep the antenna powered whenever the car is running instead of only when the HU is on.


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## Hostile (Nov 18, 2001)

The pioneer did not have a dedicated blue wire for a power antenna. Just a blue/white for remote amp wire.

Yea, I would definitely have gone blue to blue if the radio had it. 

Thanks!


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