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· Registered
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Discussion Starter · #1 ·

As I've mentioned before, I have a Scion xB. I finally got a Clarion DXZ785USB and the PAC SWI-JACK to hook it to the OEM steering wheel controls. The instructions look a little bit unclear.

Just what am I supposed to do? Shove the included resistor into the factory harness molex connector, then solder a wire to the end that's sticking out? That doesn't seem very clean or safe. I suppose I could mount the resistor on a breadboard inside a tiny project box, but that will make the whole harness job even bulkier.

I'm supposed to split the white wire from the PAC unit, and run half of it to one pin in the Toyota harness, and run another lead to said resistor and to another pin? How am I supposed to make this look clean, neat, and safe? If you've done an installation of one of these before, how did you do it?? :confused:


· Registered
51 Posts
All you are doing it putting a resistor inline from pin 8 of your factory plug to the white wire on the SWI-Jack and then also connecting the white wire on the SWI-Jack to pin 7 of your factory plug (with no resistor).

It is only two wires, so cut them back from the connector about two inches. If you want to return to factory you only have two wires to reconnect. The resistor is only a signal, and the resistor is a tiny .25 watt or less. Heat is not an issue so solder it inline and use shrink tubing over it.

You will enjoy your DXZ785USB. Imaging isn't the greatest in the stock speaker locations, but I was amazed how the TA and active setup improved the experience in my Scion.

· Registered
2,381 Posts
Discussion Starter · #5 ·
Here's what I'm emailing to PAC right now, verbatim:

Good morning,

As per the topic, I have a 2006 Scion xB with steering wheel controls, a Clarion DXZ785USB, and your SWI-JACK control unit. I also have a Scosche intermediate harness to go between the Clarion and the factory wiring - it came free when I ordered the deck. I don't have a lot of time to throw at the stereo project I'm working on, so I want to do things right the first time.

To that note, I'm having some confusing regarding the wiring of the SWI-JACK into the factory wiring and the Clarion, and I have a number of questions. I appreciate your help.

1. Regarding the 20-pin Toyota plug in the dash, your tutorial states: "The connector is viewed from the pin side not wire side." I assume this means that I'm looking into the "business end" of the plug - i.e. with the pins facing me?

2. "Connect pin 6 wire to ground." Does this mean I need to use a tap splice and run a second wire to a common ground point? What does the wire already connected to pin 6 lead to?

3. "Connect pin 7 to the INTERFACE's White wire. Connect one end of a 150 ohm resistor to pin 8, then connect the other end of the resistor to the INTERFACE's white wire. So basically you will have two wires, one with a resistor in series, connected to the INTERFACE's White wire."

This is the part that's bothering me the most. I see that I need to take the white lead off the SWI-JACK and essentially split it in two - one lead having the resistor, one a direct connection. What's the safest and cleanest way to do this? Should I use a breadboard and a project box to create a Y-junction, and run leads from that to the respective pins?

What are the respective wires coming from pins 7 and 8 already connected to? Am I supposed to cut the harness within the dash and interrupt the circuit, or am I supposed to use more tap splices?

4. "Black wire: Connect the SWI-JACK 's black wire to chassis ground. This is usually a black wire on the aftermarket wire kit.
Red wire: Connect the SWI-JACK 's red wire to a switched +12volt wire. This is usually a red wire on the aftermarket wire kit."

The red wire is fairly straightforward. Do you recommend I solder it into the joint I'm doing between the Clarion harness and the Scosche intermediate harness, or directly into the back of the factory plug referenced above? Again, with the black wire - should I be bypassing harnesses and going to a single-point common ground on the dashboard frame?

I'm confident on being able to solder and heatshrink the Clarion harness to the Scosche harness, zip-tie it all, and hook it up and mount the Clarion. As you can see above, I'm not so confident on my ability to hook up the SWI-JACK.

I want the harness to be clean, neat, and reliable. I'm trying to adhere to IASCA/USAC standards - not that there are any competitions around here, but because it's a good idea.

If I have to, I'll have this professionally done. Let me know what to do. I hope you can help.


Matthew [last name]
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