Number plate lights
 

Hi, I have a nissan sunny 1.4lx auto,1993 and the number plate lights have stopped working, all the other lights at the rear of the car are working perfectly. I have checked the fuses which all appear to be ok. There seems to be no power getting to the number plate lights, I have checked this with a voltage checker. As the car is quite old and I don't want to pay hundreds to a garage to pull the car to pieces, can anyone tell me if it's ok to jump off of the back light wires to get power to them. I asked someone in the car trade and they said it could be done quite easily. Can anyone back this up and would I need to up the fuse rating to the back lights. All help really appreciated because as it's xmas I'm really strapped for cash and this is just another headache I don't need. Thanks so much.