New head unit problem

[axelfols]

Hi, i had to change head unit as multichanger had unrepairable fault. Connects to i-pod and all is well however, when volume is low there is a faint "whine" coming from all speakers. Also if you listen very carefully whilst indicator is flashing there is a very quiet clicking as the indicator flashes. This never happened with original head unit. I took it back to installer who told me problem was due to having amplified speakers. However when i got home i noticed that fault(s) don't occur when engine is switched off. It sounds petty i know but, when driving with passenger it can sometimes be very irrititating (the noise not passenger generally!!). Should i go back to installer??? Thanks in advance for any help.

 

[Emmo]

If its just the headunit you've changed then i'd check the earth, its probably a dodgy earth, so try a different earthing point and see if it improves.

 

[AndyMac]

Yes earth the chasis of the new HU directly to the chassis of the car.
The problem is alternator whine, i.e. the new HU picking up electrical interference from the alternator, which is why it will go up & down with the revs.
Is it only when using the iPOD or is it across all sources?

 

[axelfols]

it happens with all sources.???