Cigar lighter

[wildcard]

I replaced the lighter in my truck a while back. It's been working fine until a few days ago. It won't get hot or run a fan. I checked it with my tester and the hot is getting fire but the inside wall where it grounds seems to bee the problem. When I went to check it, I stuck the probe in there and it was magnetized. And not working as a ground.
What could be causing this? Could the hot be shorting and cause it to become magnetized?
I'd appreciate some kind of advice as to where to start looking.

Benny

[68RGR]

First, a "short" in a DC circuit is an unwanted connection to ground OR to any other conductor. That is, two positive conductors could come into contact and be "shorted" together. Ideally, the resistance between the positive conductors and ground is infinite when no load is connected - In this case, when the lighter is not pushed all the way into the socket.

If your lighter socket was truly shorted, the fuse should blow. Because that is not the case, there is no direct short. Plus, I suspect you would have noticed some heat at the socket if there was a high resistance short to ground.

I guess it is possible that the heating coil in the lighter is generating enough magnetic flux to magnetize the socket.

I have seen cases where a slight sheen or oxidation will form on metal that has been heated. This could insulate the inside of the socket shell enough to prevent good contact between the lighter and the socket. You COULD try using a plumbing fitting wire brush to clean the inside of the lighter socket AFTER disconnecting the battery. But, the oxidation may return if that's what is going on. Or, you could make absolutely sure the outer shell of the lighter socket has a good ground by removing it and cleaning the areas where it contacts the steel dash.

If I recall correctly, there are two wires connecting to the socket - One is the lighter's hot wire and the other is for the light that illuminates the word "LIGHTER" - Neither is a ground wire. I learned that very well when a previous owner of my truck replaced the lighter socket with an aftermarket unit that had no lighting terminal. He connected the light wire to the ground terminal on the aftermarket socket. Of course, the next time he turned the lights on, the dash light fuse blew. It remained that way until I got the truck and figured it out.

Once, the fuse for my dome light picked up a little corrosion when the truck wasn't used for a while. Removing the fuse and reinserting it cured the problem. Sometimes, it doesn't take much to stop those little electrons from flowing!