Thread: 12 Volt Wiring Question

It's just power in to the cig port. Should not be polarity sensitive.
There may be a LED light ring around the cig port though which is polarity sensitive, so pay attention (it will either light up, or won't, depending on polarity, as LED's are a diode- ie opne way check valve for power).

The CIG lighter mechanism itself works as a giant resistor, hence it heats up, glows red, and lights the doobie.

Connect your wires, put your multimeter across it, and it should read 12V.

... on second thoughts, the port itself is not polarity dependent, but not sure if there is a standard for wiring this, as the devices you plug into this port MAY be polarity sensitive.
If this were the case, I'd consider the centre pin deep inside the cig port to be positive, and the outer ring which is the most exposed to be negative.

Usually the wire with writing on it would be positive, but not always. Best of with a multimeter to check this - you can get a cheapy of fleaybay for a few dollars that will tell you pos from neg and do 12 volt stuff easy, but I wouldn't go testing the mains with one of them.

Yes multimeter or a simple test light clip the testlight clip to a good ground of your rig and touch the wires with the probe of the testlight. The positive will loght up the testlight as you are completing the circuit the negative wire wont. The centre point of the lighter socket must be positive.

Photos may help. Which wire goes to centre pin?. Is that the positive?