VY 2004 TRAYBACK Parklights fuse blows

[Garp]

Hello this is my first post on these forums , i purchaced the ute about 6 years ago and havent had any issues with it , mecanical or electrical until a few days ago when i took it in for an inspection, they found the park lights not working , later i took the globes out and they were both blown, so i replaced them and they still didnt worked , so i checked the 10 amp fuse under steering and it was blown also , i replaced it but as soon as i put switch to park position the fuse blew , i pulled out all the other fuses but park fuse still blew , did a visual inspection at the back lights wiring but evrything looked ok.
I also hosed down the vehicle engine after a degrease prior to taking it for an inspection and i am thinking maybe i created the problem,
Any feedback would be much appreciated i tried a few tests with multimeter but not really sure if im doing things right. Is this a common isue on these utes.
Cheers

 

[Lex]

Do your brake lights work?
Maybe the filament broke & is shorting out?
As the + for the taillight is touching the + on the stop light?

 

[Garp]

Yes all lights at the back work except for the numberplate light i know from the electrical diagram that its part of the circut , i check it looks ok

 

[Garp]

With the igntion and switch off I did a multimeter reading on blown fuse socket and got a reading of 12. something on VOLT DC