Clarion head unit not powering rear door speakers

[Resjudicata]

Hi guys. I just picked up a 2008 Expedition XLT with the base audio (no sub, single CD). This is my first post on this forum. I used to have a 2002 XLT and am glad to have a big vehicle again.

I just installed a Clarion NX404 head unit to get navigation and bluetooth. After I installed the head unit the rear speakers are cutting in and out. About every 20-30 seconds they turn on at very low volume for about 5-10 seconds and then back off. The fronts are working fine.

I re-installed the factory single CD head unit and it powers the rear speakers fine (as it did before the swap). So, I went over the Crux SOOFD-27 wiring harness I used in order to make sure I had the rears wired correctly. They are. Therefore, I think the problem is with the Clarion head unit.

I'm trying to determine whether the Clarion is malfunctioning or whether the head unit simply can't drive the rear speakers for some reason. I think it would be the former and the head unit is simply bad out of the box.

Can anyone tell me if a head unit that is capable of driving the front speakers would, for some reason, be incapable of driving the rear speakers?

Thanks,
Chris

 

[Resjudicata]

Nevermind. The guys at Crutchfield helped me figure it out.

It turns out that the rear seat controls were still partially active. They were cycling on and off which is what was causing the on/off situation. Also, the volume for the rsc was starting out low which is why the volume level was low when it did cycle on.

I pulled the plug for the rsc and jumpered the rear speaker in pins to the rear speaker out pins on the same plug. Problem solved.

I'm not sure if the PAC harness would keep this from happening. It might.

Chris

 

[jjbusa]

do you have any pics of this? where is the plug located?

 

[Resjudicata]

do you have any pics of this? where is the plug located?

I'll pull the panel and take a couple pics showing the plug and the pins to cross.

Chris

 

[Resjudicata]

To get to the plug for the rear seat controls you need to pull the panel on the top rear of the console. The panel houses the two cupholders shown in the following photo. Pull the panel straight up releasing the clips.


The plug is readily visible attached to the rear of the rear control panel. The plug is blue'ish and has a grey latch holding it in place. Push in on the tab holding the grey latch in place and rotate the grey latch releasing the plug.



Then jumper the pin receiver holes as shown. The pins 4th and 5th up on either side are jumpered together (these are the speaker Neg in to out) and pins 3 and 6 on either side (these are the speaker + in to out).
URL=http://s35.photobucket.com/user/pacmanresjudicata/media/bypass6.jpg.html][/URL]

This bypass sends the speaker signal directly from the head unit to the rear speakers. Obviously, this also disconnects the rear seat controls, but that was the intention anyway with the new head unit. The new head unit is not rear controllable (I don't think) and the Crux adapter I used keeps the front Aux In port active instead of the rear seat controls. The front Aux is more useful to me than the rear controls.

Hope this helps someone.

Chris