Hi everyone,

So today I finally got round to replacing the broken door check straps. That went with no real hitches. Door cards off, speakers off and access through the hole was adequate to do it without taking anything else off. I learnt that tip on here. Forget the poster but if you read this and it was you...thanks.

But since completing the door checks. I've had a random problem turn up with the aftermarket Sony head unit that I fitted last year.

Again thank ls to Forum help, I went with the method that bypassed the ignition system but required you to turn the unit off and on manually. For me it seemed the better option. Thanks to the guide and advice on here, I completed the job myself and it's worked without any fault until today.

Now, I can't turn the unit on or off without the car ticking over. If I turn the radio off, I have to restart the car to get it to do anything.

Surely there's nothing in the doors that could be linked? We only had to disconnect the drivers side window switches. Nothing else was played with.

Answers on a postcard ?

Did you disconnect the battery at all? I'm suspecting stereo settings more than car fault but without understanding how the switched live is wired i cannot be sure.

Nope. Didn't disconnect anything other then the driver side windows switch.

The guide had two methods, one involved a cable to the ignition and the other relied on the user to switch the radio on/off. I went with that option. I preferred manual control rather then the ignition anyway.

Just to make it more interesting. We've not changed any settings on the head unit.

Are you sure you've not pinched or grounded one of the speaker cables while you were working on the doors? Might have some strange consequences if you have.

Have you checked all of the door's functions that you were working on. i.e. central locking works, windows go up and down, mirror adjusts, speaker makes noise?

It seems an odd way of running a head unit to not have an ignition switched live on it but I guess that work work best for those that don't want to mess with wiring. A switched live is easy enough to jump off the steering column though, as the cruise control plug has one. There is of course the fuse box down by the steering column too, so plenty there to pick from.

It's difficult to give you much concrete without knowing how it's been wired. The cars run a canbus setup so if you're doing something that is upsetting the canbus system (I know not intentionally but it's Italian electrics after all) it might well chuck it's teddies out until you reset / power cycle it.

unless your head unit has a switch on it so you can tell it you want to just use a permanent 12V, you'll have to connect the permanent 12v supply and the ignition switched 12v supply wires from the head unit to the +12V of the car, thereby telling the head unit that ignition is on all the time and to just rely on its own buttons for power on/off. Some have an arrangement of bullet connectors so it is easy to splice the incoming 12v onto both wires of the head unit.

Presuming that you've done it that way (as it worked before) then as others have said you must have done something weird with the speaker wire. Try disconnecting the speaker ISO plug (8 wires/pins) from the back of the head unit and see if it starts responding to buttons properly (though will obviously have no sound). Often the connector from the actual metal of the head unit will lead to 2 multi-pin plugs (ISO plugs), one of which is speakers and one is various voltage/ground/sensors etc.