I have recently installed the ND g500 and the F500BT in my Vauxhall Vectra. The install was fine and all works ok other than 6 deep beeps/pulses when I start the car.

 

I used a quadlock to ISO T harness that would be used to install a parrot kit and the above symptoms happen when connected to a switched ignition (blue wire on the T Harness). If I connect the blue wire to a 12v source which powers on when the car is unlocked (ie ashtray light) and powers down after 5 minutes the beeps car then be heard as soon as the car unlocks as well as when cranking the car. It seems to happen when the car initially powers up?

 

I know the stereo breifly turns off whilst the car cranks, if this cuts the 12v constant to the amp could this cause the odd behavior?

 

Any help would be appreciated.