Need to install a cdplayer in 70 chevy truck?

Because of the year of the truck you will not have any wires pre-wired in the truck, go to a Radio Shack, car audio store or Best buy and buy yourself some speaker wire for vehicles, about 5 ft of 14 - 16 gauge yellow wire, 5 ft of 14 - 16 gauge red wire a couple of 10 amp fuses and 5ft of 4 gauge black wire.

You are going to run the Yellow, Red, Black wires together from the radio space where the radio sits in down to your steering column, the speaker wires will go to your speakers from the radio, a + and a - lead to your speakers and connect them as needed.

Now back under your dash you will connect the yellow wire from the radio to the 12 volt + wire under your steering columns 12 volt power wire with a fuse inline, if you hook up a test light to this wire it will light up the test light without the car switch being turned on, the red wire will hook up to your ignition switch wire and your balck wire to the vehicles ground chassis, basically ground that wire to a non painted surface of the vehicle. This radio needs to be hardwired like I explained.

Good luck and hope it helps.
Lex.