Ok basically what's happened is that i got a friend of mine, who's more technically competent than me (or so i thought), to install my car stereo. Since then i have not been able to get the car to start. I have since removed the stereo. All the electrics seem to work, but when i try to start the car all power is cut from the electrics. Only when i disconnect the battery and reconnect it will the power return.

Any ideas on what could be causing this? Have checked all the fuses and they seem to be ok.

 

very odd situation and I would point at a ground or he has wired it to the ignition/immobilizer so ensure all the wire he messed with are connected right and solder them

 

I've had a bit of a look and the only wires which have been touched are the ones related to the stereo: the permanent 12v, the vehicle earth, the instrument lighting one, the "speed signal for automatic volume compensation", the 8 speaker wires and the antenna one.

My mate has also since confessed that he misread which wire was which and the problem mentioned in my first post started occuring when he tried to start up the car with the wiring incorrectly connected, if that's any help to determining the problem.

So i guess i'm unfortunately carless at the moment since all it will do is make a single clicking noise when i try to start it; i'm stumped.
Any further help would be appreciated.

EDIT: I just forgot to remove the negative lead from the battery and subsequently blew the stereo fuse. I replaced the fuse. Separated all the wires and taped them securely to ensure they wouldnt cross, with the stereo completely disconnected. And the car started with no hint of the problem.

I then attached the permanent 12v wire to the stereo and the ground too. The car started but the stereo would not work. So i disconnected the battery again and hooked up the "instrument lighting" wire (audi end) to the "illumination" wire (stereo end). The problem reappeared directly after doing this, and i have been unable to fix it again.