87 s10 headunit install, Urgent help needed

Ok my first time wiring in a CD player and i finished with no power to cd player or dash lights. There were 2 black wires and a grey wire left. Are all the black wires grounds? Help me out.

can anybody give me a picture of their wires or something because i have more wires in the dash then there are coming off the back of the stereo.

Black should all be ground, but why you have two left over in the dash is a mystery. Double check your connections with this:

MEM ORANGE +
PWR YELLOW +
GND BLACK -
ILL GRAY +
DIM BROWN
ANT PINK +
Speakers:
RF LT GRN +
RF DK GRN -
LF TAN +
LF GRAY -
RR DK BLUE +
RR LT BLUE -
LR BROWN +
LR YELLOW -

What brand head unit are you putting in? Are you sure it works? Check for power between Memory and ground and power and ground (make sure you're turned to ACC).

Im putting in a sony cd player.

Ok this is how it goes,
black- to black(- to-)
red+ to orange(allways hot)
yellow+ (12v+) to yellow (hot in acc and run)

and the speakers are self explanitory. The red off the cd player is thinner than the yellow so i thought it was just to keep the memory so i made it allways hot.

So i have a grey from the truck left along with to blacks.
Also have a ANT REM not connected from CD player b/c i dont have a power anttenna.

Out of the back of the old stereo there was a brown wire that was not hooked up, but thats off the stereo not the truck. I have it now so the truck runs but i need to get all of this put back together.

alright, busted out the volt meter and found out my constant hot wasnt hot. So i ran a new wire from the fuse block and it works! Thanks goser for the reply.