Headlights blow a fuse

[Iain]

Turning the headlights switch to position 1 or 2 (sidelights or dipped) results in the 10A fuse in the bottom left of the fusebox (fuse 13) blowing. This results in the headlights and drivers side rear light working, but the passenger side rear light, all behind-dash lights, the behind-clocks lights and the warning buzzer failing to work.

I have recently fitted a digidash w/ transducer and full alarm/immobiliser, although I believe the fault occured before this.

I have just had a quick whip round and checked eaths for the main car loom in the middle behind dash and in the boot and they seem okay.

Can anybody offer any help?

Thanks in advance,
Iain.