question for all car audio wizzards

[novellino21]

My sister has a 1990 honda accord 2door 5speed and i put in a older sony head unit in her car. I bought two wireing harnesses from circuit city so that way it's a plug and play type of deal and not figuring out what wire goes where. Well the problem is that the deck wont turn on but it will accept and eject a cd fine. So it's getting some kind of power but still wont turn on.
I have a test light and wondering what wires to test to see what is getting power and what isn't. i called CC but they wont help me b/c they didn't install the deck.
I think it might be a bad ground but not sure on how to test the theory.
Should i connect the one end to the black/ground wire and the other to the yellow wire?

[FavoriteMystaque]

The yellow wire should be constant 12 volts. Usually, a red wire in the harness provides 12 volts switched with the ignition key. I think you are missing that power. (The test light should be grounded at the black wire, it probably will light when you test yellow wire.)

[HolyRollerzC3]

i just had this same problem with my brothers 1990 accord, its a 7.5 mm fuse under the hood, says radio right on it,m sony sucks like that...

[novellino21]

i grounded one end of the test light to the black wire and touched the yellow wire with the ignition off (it shouldnt matter cuz its a constant 12v) and it is getting power. But then i grounded one end and touched the red wire with the ignition key on and its not getting power. I am thinking what if i spliced the red wire into somthing else that does turn on with the ignition key, but what could i splice into?

[novellino21]

ok so i figured it out, the red wire that is suppossed to get power when the key is turned on wasnt getting any so i jus simply connected to the brake/blinker fuse under the dash so this way the deck turns on when the key is on and vice versa.
It's a getto way of do'in it i know, but for now it'll work till i find more time to do it differently.

Thanks contour.org:)