"-" & "+" confusion on car audio?

[fatboy]

i think one of my speakers in my car might be wired wrong i think i might have gotten the - and + switched. is there any trick to tell which wire is + and which is -

[mex99b1084]

most car audio wiring has a positive symbol on the positive side of the wiring. as long as you hook the primary side up correctly then you know the other end will be right if you do the same at the other end

[DanielK]

Yes there is - connect a small battery (AA or AAA or C) with some wire to the speaker for a moment. If you connect the positive of the battery to one terminal and the negative to the other, the cone will move out slightly if the + of the battery is connected to the + of the speaker. This is an old trick and it works well.

It will not harm your speaker in any way despite what anyone says. I have done this many times. Just make sure the wire going to your amplifier is disconnected.

[PaulF]

Daniel K has a good answer, but still remains the doubt that the wires may be reversed at the radio side.
Another test is to play a sound rich in lows, listen carefully, switch the wires, compare sounds.
When one speaker is reversed respect to the other, there will be some low frequency cancellation, but it may be hard to tell.

If it sounds good to you, one way or the other, just enjoy the sound and don't worry about the polarity.