How do you test a Pioneer b4 buying?

[MARCUS]

Help! How do you test a Pioneer HU before buying it? you test it through the battery right? I just want to see it light up and read a CD. There's 3 wires: RED, BLACK and YELLOW

Do I combine the RED & YELLOW and tap it onto the Positive Battery terminal?
Then the BLACK to the Negative terminal?

Just want to make sure, don't want to blow it up

[chua_riwap]

Why not let the sales clerk (from where you're buying the unit) do the testing before buying the unit?

[MARCUS]

Why not let the sales clerk (from where you're buying the unit) do the testing before buying the unit?

Well I'm getting it 2nd hand.

[MARCUS]

Is it safe to combine the RED(12v Ignition) and the YELLOW(12v Constant)?

If i connect just the yellow or just the red to the positive and the black to the negative, the unit does not light up.

Any suggestions GuRU's?

[MARCUS]

Tried it anyway and it works, I figure they're both (+) so what could go wrong