3 replies to this topic

[BigAnt]

Hey Brains Trust,

Just a quick question. Should there be any voltage at all on an accesory wire when the key is 'Off'?

I'm getting 0.5 of a volt on my wifes 92 Celica. I get the full voltage when key is turned to 'Acc'.
Went to investigate after the Pioneer DEH-8950 started playing up. Ended up with a flat battery after a couple of days with the face off. When the face was removed it was having issues - aerial half down, key was turned to off but headunit stayed on. When face was removed, face motor didn't retract.
Suspecting a short between the 12v constant and acc wire. Took the headunit out - admired the job of the 'professional' install done by JB-HIFI at Marion (before I knew of MEA) - Lots of black tape, wasn't game to look under tape but there was a copper strand coming out from under one piece of tape

Plugged the headunit back in and all seems to working fine again. Unplugged the headunit just to see if the battery loses any voltage over night.

Thanks,

Ant.

Edited by BigAnt, 01 February 2012 - 10:18 PM.

[Big_Valven]

Keep up with the diagnostics - ie with the headunit disconnected overnight. There may be an intermittent wiring short somewhere under that tape, or they may have mistakenly grounded to the wrong spot, or accidentally connected something wrong.

To add though, I wouldn't be overly concerned with 0.5 volts on acc with the key off on its own, but it's evident something else is awry...

Edited by Big_Valven, 01 February 2012 - 11:21 PM.

[ubernoob]

Every car I have put a HU in has had a small voltage present at the acc wire with the key off, I was worried the first time I measured it but every other car since(about 6) has had a similar voltage there.

[BigAnt]

Thanks heaps fellas, car is still working fine. HU had been working fine for a couple of years until now. Ill leave it a couple of days just to make sure, double check everything and put the HU back in, see how it goes.