Fuse popping for dash lights and no number plate lights

Hi, back again needing some help with electrical gremlins, decided to change my dash clocks over as my caddy was imported so had km/h clocks put everything back together and the dash doesnt light up and i have no number plate lights (checked dash bulbs before fitting with continuity tester) as the wiring has been butchered i dont necessarily trust the colours are what they are supposed to be, but thats not to say that it hasnt been done right, found the fuse that be poppin' to be a 20 (yellow) and every new fuse pretty much pops instantly. im assuming the dash lights and numberplate lights are on the same fuse or could this just be another of my many problems haha.

another issue i have (pre clock change) is my passenger side rear light goes off when i apply the brakes

any advice or things to check is appreciated cheers 

The tail lights should be on a different fuse rather than both on the same.

On the early mk1's the insturment lamps were not fused, so they were easy to burn the wires and pop a fuse.

Later ones as in 89 and above they had a separate fuse for the instrument lamps.

Telling us the year of your ride helps us help you a tad better as we know which wiring we have to look at.

Hi, so the caddy is a 1984 but has had an engine conversion to a mk3 2.0l 8v (all done when it was in South Africa)