Speakers work with ignition but not when engine running?

[_Tom]

Not sure if anyone can help. A lad at work has a MK4 golf which he's not long bought. Now, when the ignition is on he gets sound to all speakers as normal. As soon as he starts the engine he doesn't get sound to the speakers but gets sound to the sub which has been installed.

Any ideas what that would be?

 

[Harbinger]

Has it always done this? it could be something like the 12V constant and the back up are the wrong way around, might be why the sub always works as it's always live and the power switches over to backup when it should be live, killing the power to the speakers, maybe.

 

[_Tom]

No. He's just installed a new head unit. I did have a quick word and he said he's wired the remote for the sub to a wire with B+ on? Im guessing that's his issue as it doesn't sound like a switch live/remote.

 

[Harbinger]

The remote line is probably tapped into the constant power feed for the amplifier in the head unit, the head unit should have a remote out line separately in the loom, i'd disconnect that and plug it back in, should be either a red or yellow wire that's been diverted from the head unit loom?