Outside Light Testing

[Onherown]

I have a 150W outside pir light which stopped working I changed the lamp, still did not work. So I replaced the whole unit, still does not work my next step was to replace the wiring but I think there is power coming through it as the live touched the earth or neutral and tripped the rcd. I have now taped the ends up individually!!
1. How do I test it safely to see if the cable is still ok
2. If it has got power then could it be the outside switch which is faulty
3. If not the above what could it be?

Thanks for your advice

 

[sealeon]

you need a voltage tester.If it tripped the RCD so none of your sockets worked?The chances are and it should be fed from a spur with a fuse you have probably blown that fuse