Dear Car talk; on a cirgarette lighter circuit; are both wires hot or just one hot and the other one not; I’m tring to fix my cigarette lighter. thankyou 
Yes, one is hot (often red), and the other wire (often black) goes to ground.
The one attached to the middle is generally the hot, and the one attached to the side is generally ground. I have seen some configured to have a two-wire connector in the center, tho. Good luck.
thankou for responding bustedknckles; I tested the wire with a test light; everything is good; I’m getting power to the hot wire; but when I hook both wires to the cig lighter it still not responsive; I did a by pass and made the test light the ground to see if it was the ground wire; still noghting; do you know if cig lighters themselves go bad for some reason; thankyou for your time Frank
The heating elements do burn out on cigarette lighters. I’ll bet a replacement element may even be available at WalMart. Here is a money saving tip: Don’t replace the element and quit smoking. You’ll save $5.00 not replacing the element and much more than that on cigarettes.
thanks for the advice tiredag; lol I don’t smoke; it is for my cell phone charger; but I agree with you I would save a lot of money on cigs; do you know does the heating element come off easy? I’ll go to the store tonight and get one and try; thankyou Frank :O)
Two issues here:
-
If you are using the socket for your cell phone, it doexn’t matter whether or not the heating element works. The heating element is attached to the knob that goes into the socket. If you aren’t getting power to the socket, then your phone charger won’t work. I had this problem in a 2000 Ford Windstar that I owned. I had no power at the socket. In my laziness, I just plugged the cell phone into a socket in the rear compartment for a long time. I finally got curious one day as to why the front socket didn’t work. I removed a trim piece and found the socket had never been connected from the factory. I plugged the wires into the socket and it worked fine.
-
If you do want to replace the heating element, it unscrews from the knob, or at least it did on the 1955 Pontiac that I owned years ago. I believe that the cigarette lighters still work the same way. As I said, replacing the element won’t get power to the socket.
It may be that the center contact in the socket is corroded. Disconnect the power and try to scrape the contact with the end of a knife.
Just a addition.If you are doing some electrical diagnosis (something simple like lighting,no data busing stuff) the cig lighter is a great place to pick up a ground.
I have a cable set-up (from Mac,Matco etc) that you plug in the lighter socket,now you have a quick and easy ground and hot.
Often it’s hard to get a cig. lighter plug (like on your cell phone charger) to make good contact in the lighter socket. Try either rotating it in the socket or pulling it out, turning it 1/8th of a turn, plugging it back in—repeat until you get some power.
thankyou for responding oblivion; I’m actually getting no juice to the socket itself; I have a test light; the hot wire is good; my test light comes on; but when i put the probe in the socket the light does not come on. so I’m guessing a bad socket somehow thanks again , Frank