I am in the process of removing the head unit the previous owner installed and came across 2 wires which are not coming from the car's harness.

One is a blue wire that looks like its coming from the driver side. The blue wire is connected to a blue/white wire in the radio harness.

The other is a black wire that seems to lead into the bottom of the dashboard. I am not sure where that leads either. If anyone could give me some advice I thank you in advance!

 

Was there an aftermarket subwoofer and amplifier before? If so, the blue wire could be the signal wire for the amplifier to power up. Does the blue wire travel to the trunk? The black could be a ground but not sure.

 

Yes it had a sub and amp. Is there a good path for it to get to the trunk going in that direction?

If the black wire is a ground, where do you think its grounded to? I tried to follow it but it disappears deep in the dash.

Thanks for the reply

 

blue white from radio harness is amp turn on lead..so the blue wire must be remote turn on to the amp... black maybe a chassis ground it most likely runs to a ring terminal connected to chassis ground.. this is done because some oem ground wires cater to multiple devices so running a separate ground makes better sense as it will eliminate any possible ground loops...

 

Thanks a lot, makes lots of sense.