Technical Strange issue with the pre-wired stereo neutral

[mousTacchini]

I've recently wired some front speakers in the pods, an underseat sub and a head unit into my Panda (no previous speakers although it did have the stereo sized shelf already with the live and neutral wire behind). I tapped into the brakes for ignition switched power

Once everything was all installed and I connected the battery, my head unit would only power on for like half a second and then turn off again and repeat. after blaming the head unit that had been sat for years and buying a new one, the new one did the same :bang:

I've now realise that if I earth the stereo's neutral on the ignition switch it works fine.

Does anyone have an idea what could be causing this issue with the pre wired stereo neutral?

 

[Dragon Man]

hmm bad earth under the bonnet? try cleaning the main dash earths just under the battery see if that helps.. you have a cig lighter socket? try earthing to that i think however it shares the same earth as the radio though.

 

[mousTacchini]

Yeah that's what I assumed it was, strange as the cigarette lighter socket works fine even drawing 2A for a phone.. Ended up wiring in a new ground to one of the seat bolts but will try cleaning the dash earths to see if that works.

Thanks for the help!

 

[Sjvarley]

May be the head has a voltage drop sensor. So if the volts drop due to resistance when powering up it self protects !!