MX5 radio installation

I have just bought a 95' Mazda mx5 1.8 and it has no head unit at the mo so i went out and bought one.... the problem is that a previous owner at some point has sliced and diced the headunit wiring so i cant make heads or tails of it, its all bullet connectors... I'm very handy with cars but autoelectrics arent my speciality.

Can anyone provide any detailed info on what should be where or a diagram.... I will upload pics in the morning.

Thanks in advance

Richard