help head unit

[newboy2thenova]

on the nova stereo loom there is 4 wires black red brown , n yellow

but wot do they do?? tryed conecting my jvc headunit up but it wont come on are do any thing..its brand new and iv seen it working in the shop, please any help welcome

[gary_1.2Merit]

black=ignition live
red=constant live
brown=earth
yellow= not to sure but i think the only other power cable is illumionation but mines white/green.
the only other wires are for the speakers