HU Goes Off When Ignition On

[eternal_inertia]

I've tried everything with this but have had to give up and seek advice. We just got a 1997 Golf with a broken radio so I've tried to fit a Sony HU using the same wiring loom that was already in (that was a Sony too) so I've managed to get it working without the key in but when I turn on the ignition the HU goes off.

So then I've tried swapping the red and yellow around but still the same problem. I can get it to work fine with the key out of the ignition but just cannot get the HU to stay on when the car is running.

I've noticed higher up the wires, before the ISO loom, two of the wires have been bridged and I'm sure that's causing the problem but can't figure out how to fix it.

Here's what I'm talking about -



I hope you can help, I'm sure I've tried the wires every way possible. red-red yellow-yellow, red-yellow yellow-red, yellow&red-yellow etc. HELP!

[troublestarter]

take that joiner out as that is joining the permanet live to the ignition sense wire
that should dolve the problem

[eternal_inertia]

Yeah I've tried taking the bridge off and it still works the opposite way around, on when key out, off when ignition on. It seems someone put the bridge there for a reason.

I think I'll have to have a play around with every possibility, note it down and post my findings.

EDIT - Ok so I checked the other night every possibility and came up with these findings -

With the Joiner Removed-

Red to Red and Yellow to Yellow
HU comes on without the key in
Flickers but stays on with key in
Goes off with key turned

Red to Yellow and Yellow to Red
On without the key
Flickers and stays on with key in
Off with key turned

Red and Yellow connected to Yellow only
HU does not work at any stage

Similar things happen when the joiner is connected, whichever way I just cannot get the HU to stay on when the ignition is turned.

[troublestarter]

the fault then is with the thin brown/red
you will need to run a new cable from the back of the h/u to the black ignition wire on the back of the fuse box or at the steering column