C70 GT Dolby audio issues
 

I have just got a c70 t5 GT on an 03 plate and the Dolby system is not working. There are 2 main speakers on the doors and only 1 is working and the centre's speaker is also not working. Is there any common issues with this system. Have have checked the wires behind the head unit and even unplugged some and it does not change the sound so I guess something is not working ie an amp or processor

Could be the wiring in the doors. Can sometimes fail as it's being manipulated frequently with floors being opened and closed.

It may sound a daft question, but are you operating the system correctly?
The centre speaker only works when the head unit is set for it to work, also the same with the surround sound and bass speakers behind the rear seats. There is a little button top right of the head unit that operates the system and it only works when the CD player is on, not the radio - I think.

The amp is in the boot behind the left hand trim panel. Remove the trim panel and there are two fuses sitting on top of the amp. Door speakers should work at all times, so as said above, could be wiring or a blown speaker - they are known to blow.

The centre speaker has a weak spot, the magnet falls off it and that kills it. There is a newer model which has bolt going through it to secure the magnet.

Door speakers can be as simple as a disconnected wire, if the door card has been taken off for window adjustment or such. Otherwise it may be a faulty wire, from door operation.

The SC901 can operate in three different ways, normal stereo with front and rear, 3ch stereo with front, rear and centre, and Pro Logic with all speakers active and focus on front + centre, with rears as echo speakers, the effect can be adjusted and faded as you wish.
This three effects can be used in cassette, CD and radio mode.

The SC900 was an older version with less functions.

The speakers could blow on these if it was played at very loud volume for a long period .. connect an AA battery cell across each speaker , you should hear a click

Check the balance control and also “centre volume” knob. Just a quick check to do before getting fully stuck in and removing things

Thanks for all the replys. The mode button is no doing anything just staying on stereo. One speaker in each door is working. When I took the head unit and unplugged some of the connections nothing changed sound wise. I will have to check the fuse.