radio wiring

[85 sd2.5]

if i were too wire in a radio where would i put the illumination wire (from the jvc deck) to the truck fuse panel or? also the wire that keeps the settings on the deck some kind of constant i guess but help is needed thank you

[plenzen]

If you were to hook it to the "Constant" power supply the illumination would be on all the time = dead battery. The constant power is for the clock and the channel memory. ( low amperage draw )
If you want the deck illumination to come on with your head lights then splice into your dash light circuit someplace where you can get at a wire.
It's been my experience with the wiring in these little guys that it's pretty wimpy overall and does not like being messed with.
If it were me I would hook the illumination wire to the "switched" power wire and go on from there.
IMO that is

P