Passat aerial amplifier fault

[weerobstar]

Hi just new to the forum,

have a fault with my aerial amplifier ( full of water )
checked for a 12 volt feed at the short lead at the gearstick,
only shows 12 volts when radio switched off then on for about 6 secs
is this normal or a fault with radio ? ( checking at middle of aerial lead )
does radio have to see a load if not disconnects live feed to amplifier ?

Passat 2001 with factory fitted radio

Cheers

[snapdragon]

Interesting, I had this problem at the aerial when I measured the voltage. I replaced the aerial base (which was just corroded) and still have rubbish reception, so gave up as I don't use it much.