Radio problem

[threespins]

Hi,
hello again, not posted for a long time as car gives no bother, until now.
The car is a 2003 2.2 TiD vector estate.
Radio swops stations continually of its own accord and CD player plays for a few seconds and then swops to radio. Is it likely to be a faulty head unit or could it be something connected with the amplifier or the aerial amplifier/filter.
The reason I ask is I obtained another head unit but the dealer using the tech 2 scan tool could not get it working so assumes that the new unit was faulty. (he did divorce my original unit from the car)
I have obtained another head unit, but beforew I go back to the dealer to try again I would like to sound out your opinions.
Thanks, G.

[threespins]

No suggestions folks, so obtained another unit from the supplier and going to try that.

[P2BS]

It's not just anything as simple as having TP on, is it? It will continuously search for a radio station that does traffic announcements, and will shut off a CD & revert to Radio to inform you you're off not on a channel with TP.
What may not be helping is a bad aerial booster - in the saloons it's on the drivers side c-pillar by the rear screen. I think on the estate it may be on the passenger side under the rearmost side window (i.e. the side panel of the boot) but you can look it up easily enough. A bad radio signal (caused by a bad booster) will mean it has trouble finding a signal, hence no TP, hence channel hopping.
That's my theory anyhow.
HTH

[threespins]

Thanks for that Brendon, you may have something there, the technician said he thought the amplifier was on the way out.

[threespins]

Thanks once again, Tp; or TPY, shut them off and back to normal, why do I always assume the worse and spend money before asking the obvious!!!