kenwood hu strange behavior

I had a Pioneer AVIC that I installed in my 95 Buick that worked correctly. When I shut off the ignition, the unit stays on until I open the drivers door. Then the unit shuts off. I replaced the Pioneer with a Kenwood DNX9960. The wires were basically the same except with the Kenwood I didn't need the Speed Sensor.

Now when I shut the ignition off, the Kenwood goes off immediately. If I dont open the door, it will come back on. Since it takes as much as 15 seconds to go through its start up, it is really annoying. I am wondering if the kenwood senses the drop in voltage at engine off and shuts down. I cant figure out what is going on because my red wire(Switched) still has 12v on it until the door opens. Any idea what is going on and how to fix it?

You will need a 3 amp diode and a 4700 microfarad 35 volt capacitor, both are available from Radio Shack. I will look for the diagram, or draw one tomorrow.

I found the diagram, it was to keep an EQ on after system shut down.  I will draw a new one tonight.

Thanks, I would be very grateful. Could you please explain what you feel is going on? I am wondering why the unit is temporarily shutting off.

I think maybe I figured it out with out the diagram. Please tell me if I am wrong. I am guessing that the diode is to prevent back feed. So if that is the case:

1. vehicle 12v switched wire to diode (to prevent back feed)

2. diode to 4700uf capacitor

3. 4700 uf capacitor to kenwood red 12v switched input wire.

Thanks again for your help

You are correct in your assumptions.  Following is the diagram, just substitute Radio's red wire for the EQ's blue wire.  Substitute Vehicle switched power wire for Remote wire from deck.  Capacitor I suggested is much larger than the cap for the EQ, so you will need a 3 amp diode instead of the 1 amp diode pictured.

The problem is when you turn the key off, there is obviously a momentary drop of voltage to the Red wire of the deck.  Your old deck either had a capacitor on the red wire inside the deck, or the current demands of the other radio's red wire is not as great as the demands of your new deck.

Thanks. I will give it a try and post back the outcome. I am glad you attached the drawing because I would not have grounded out one leg of the capacitor. I would have ran it similar to how a fuse is ran. So I have learned something from this:-)

Thanks for your help. I do have one additional question. At first I wired it backwards because I couldnt tell which end was neg. One of the ends was black, so I figured that was the negative end. It worked great though. The stereo stays on until I open the door and then it goes immediately out. The only issue is it is 65 degrees here in the shop and the capacitor gets up to 110 degrees. I am worried about having it under the dash especially in the summer months.

Then I got to looking at it and thought I might have wired it backwards. So I reversed it and now it is quite a bit cooler, about 75 degrees. The issue now is that the stereo stays on for about 5 seconds after I open the door. I guess that is better than before, but I would really like it to go off immediately after opening the door. Do you think I might need a smaller capacitor? Any idea in size recommendation?

Thanks again for all your help

I see where I goofed up...I bought a 4700uF instead of a 470uF. I will pick up another one tomorrow and try that and see what happens.

In my initial text I did say 4700 mic.  I have no idea of the current draw of the red wire of the deck.  The picture was to keep an EQ powered up long enough for an amp to shut down.  The cap got hot because it was backwards.  If the 4700 keeps it on for 5 seconds after the door is open, a 470 should keep it on for 1/2 second after the door opens.  You may want to try a 100 mic device.