Strange Electrical Problem

Hi
I've just encountered a strange problem on my '95 Discovery tdi.
1. The display on the radio cassette player flashes (But very dimly) when I try to switch it on and the electric aerial motor is cycling at the same tempo.
2. The front sunroof won't operate but the rear one will
3. None of the interior lights work but when I try to switch the front courtesy light on there is a very brief glow in the bulb filament.

The radio cassette player works perfectly when I connect in my caravan
I've checked all the fuses and they are OK
I disconnected the supply to the electric aerial but the other problems remain the same.
All other electrical equipment works perfectly.

Any thoughts before I take it to an auto electrician?
Am I missing something obvious?
Thanks

I am new to landrovers but
Sounds like a poor power connection
or a bad item pulling down your voltage
to that group of accesaries
just today as I was working in the fuse box replacing a fuse that another helpfull soul suggested I nocked out a one sqare
white plug .
I had no blinkers or starter . it was loosely pluged in and just must have fallen out
once in she was ok.

its an earth problem...........................somewhere