Electric fault draining battery.

[saab900]

I have been doing some work on my Saab 900, replacing bulbs and getting one or two things to work.
The car has a Analog clock on the dashboard also in this circuit is illumination for the ignition key and electric ariel, if I put a fuse in everything seems to work but battery goes flat overnight, I cant see its the clock or the illumination lamp so im guessing its the electric ariel.
It seems to retract ok and shut off but must still be drawing power, anybody come across this before ?

[suffolkpete]

Remove the fuse and connect a multimeter set to current measurement across the fuse holder. If you can measure a current, try disconnecting the aerial to see if it stops. I've never come across this fault before, is there anything else on the same circuit?

[saab900]

I will try that thankyou and no nothing else is on that circuit.