I have a problem with the dash wire from the dash switches. When I have the OEM head unit plugged in, the voltages with ignition on are as expected measured from the dash wire at the back of the wire trunk. When I go to hook up my Alpine 9813 head unit, I get no voltage on that wire. Can someone with a electrical manual look up what it takes to power that wire so I can try and figure out what's going on here.

Thanks,
Mike

 

Well... I think we going to have to add just a little more detail to that one. I kinda understand what your trying to say but if you could give us wire colors and how its hooked up that might help us to have a better understanding of the problem.

What kind of problem are you having? The Alpine will not power up?

 

The head unit works perfectly, it's the voltage to the wire for the dash switches (Green / Red). That wire behaves as expected with respect to voltage (http://www.modifry.com/products/dci/tech.htm) when the OEM head unit is plugged into the harness. When I remove that and plug my Alpine unit with harness to the wire trunk, I get nothing on it.

 

Just so I get this clear in my head...

You have an Alpine 9813 and a Modifry DCI and your trying to hook it up to the dash controls and its not working at all?

 

That would be analogous to my situation as I do not have Modifry's DCI. I am trying to get the voltage off the green / red wire and it only reads correctly with my OEM HU not the Alpine so I'm trying to figure out what gives the dash switch circuit power when the ignition is switched, but I don't have an electrical manual.

Mike

 

Your trying to get the voltage of the Green/red wire coming from the HU or the controls?

 

The red/green wire from truck of wires whose harness plugs directly into the stock head unit.

Also, that wire gives the correct voltages for button presses only with the OEM HU plugged in (and ignition on, of course) and gives nothing when no HU is plugged in. So there seems to be some feedback to power the dash wire circuit only when a load is present, this is what I'm trying to figure out from someone who has a repair manual or experience with this.

 

Man your not making this very easy on me are you...

Ok so your trying to hookup a Alpine HU and your wondering why the dash controls don't work...

Its simple, its because your Alpine HU does not put out any voltage to power them... that's why you need the DCI or other type of unit to take over using the dash controls.

 

Of course the dash controls do not work...

The DCI reads the voltage from the green/red wire and outputs a corresponding IR signal to mimic the stock functionality. If you look at the DCI it has four main wires, +12v switched, Ground, Dash Wire (the green/red one I keep referring to), and Mute. Neither the Alpine nor the DCI, "put out any voltage to power them" as the greed/red wire is an input to the DCI as are the other three wires. It does not have any outputs (aside from the IR transmitter).

If the DCI were to put out a voltage to the green/red wire, as the circuit's resistance was changed by pressing a button the current would vary not the voltage.

I think you're a little confused with what I am asking, which has nothing to do with lost functionality. I am asking about the actual source of power for the dash switch circuit. Ignoring all non-OEM equipment for the moment, since the green/red wire's voltage varies with button presses only when the OEM HU is in place, and reads zero when unplugged (ignition on of course), I am wondering what load on what wire switches on power to the dash switch circuit.

 

I'm not a little confused I'm a lot confused

I guess I just don't understand what your trying to do. Or why you need to know it.

You can try and ask DJ Qube he should know the answer to your question. Modifry might know this one. Email or PM one of those guys.