Audio Systems: power wire, 1990 toyota camry, toyota camry

Question
I do not get 12v on the green an white wire on my 1990 toyota camry.

Answer
A bit vague there but I assume this is a wire from the car’s harness?
I also assume you have used a used 12v probe (bit like a screw driver with a lead on and bulb in it) or a meter to check both sides of all relevant fuses, yeah?
If it’s all o.k. there then check back down the harness from the head unit to find were the break is.
If all else fails then run another new wire FROM THE FUSE BOX OUTPUT and bypass the faulty one.

Let me know how you get on.
Peter