Thanks. Once again you come to my rescue. There is so much on the empeg that I've forgotten how to do.

I've gone back and taken a look at the empeg in the car. I was wrong, the pulsating does come on when empeg in standby but only when the head unit is off. As soon as I turn it on again the light goes off. Must be something to do with the way I have connected up to the same power cables. I may have to check the cabling after all. Rats! I think I have possibly connected the antenna booster cable to the blue wire which may be causing this to happen (and the only change I added when I swapped the empeg and the Pioneer around.