Remote lead / power issue

[caribsimon]

Hopefully someone could shed some light on this.

I worked on a home install in a car this morning. Nothing special, Sony headunit, running to a amp powering 2 x 10" subs. All of the wires were in tact and well connected at either end, however when you turn the stereo on, it does not communicate via the remote lead to turn the amp on. So I bridged the power and remote together and the amp works ok, however only up to a certain volume level.

The only explanation I could think of, is there is a problem with the power lead and the remote lead is actually powering the amp/subs and when the volume is turned up, the amp can't get enough power and switches off.

I didn't have much time to investigate, but I said I would ask the question on here.

Any ideas ??