Audi a3 , 2009 ever since it had a complete interior detail it has played up with lights on dash coming on and off , even with key out of igntion

Does the interior light come on as well? if so check the door switches them self, a wire may have come off and is touching earth. This is how the switch works it completes a circuit to earth for the light to come on. It's not a fuse.

can i buy a comma? says vanna white?? LOL !
ok, the battery drains, so you got a DRAIN, called phantom drain.
or dark current.!!
we use a thing called an AMMETER (DMM) to find all drains, easy

do you have one, want to learn or just wanting wild guessing.

on any 08 liberty, we check the scan tool data.
oops it shows battery low, wow even the PCM sees that.

new batteries do not fix drain.
nor dead alternators.

get it serviced, by a pro. ?

1: charge battery (rested its 12.6vdc )
2: start engine, scan tool shows, what DTC errors (post em')
3: battery voltage is , 13.3, to 15vdc running, if not charge system is faulting.
4: ok all that is ok, i then key off and measure bettery cable neg lug drain current, if 0.010a to 0.040a its ok, if over 0.1 amps its a drain.
we then find the drain cause, ASK? its not hard with a meter.
but i bet all you wanted is a wild guess.

sounds like you have a grounding issue possibly a main grounding location. inconsistant grounding of the vehicles control module will cause erratic behaviours. check under the hood for ground locations containing multiple grounds at 1 bolt location.if different "experts" have attempted repair and failed chances are they are all looking in the wrong place.dash{interior of vehicle}..actual cause.{egine compartment or under side of vehicle..ie...ground locations.}good luck and safe motoring:>

You need a new igntion lock and the system programmed to accept the new key, there is no way around this.

That's how the car was built - until the midyear facelift in 99 (the 99.5 model), the dash lights were always illuminated. Even with VagCom I haven't seen a way to disable this - the car is hardwired to light up the dash with the key on.

Hi
Check your battery terminals and make sure there not loose it sounds like a bad earth to me
Hope this helps Nick

It's the light bulb for the car electronic immobilizer.

first get out all the light bulbs then u need to test if problem same u need to tes wires if nop damage in the cables....

check you dimmer switch. the dimmer switch is what controlles the interior dash lights and dome lights. you might have acidently hit the switch and it may have pushed it up from the position it was at. if you push the switch all they up than you interior light will come one even if you shut the car off and pull the key. turn the dimmer switch all the way down and see if it still does it. if not than wait until it gets dark and go outside and turn the swich up until ou can see the dash lights. but remember if you turn it up to far the interior lights will come on.