Testing 12v cigarette-style outlets

[tantle1961]

I have a 12v outlet that is not providing power.  I have a 12v fan that I tested in another outlet that works so I know the fan is good.
I don't see any failure lights on my fuse box.
Is there a way to test my 12v outlet with a multi-meter?

Thanks

 

[Utclmjmpr]

The outer "barrel" of the receptacle is the ground side of the circuit,, place your ground probe (black) against it and place the "hot" probe (red) right down the center carefully to contact the center post.. Place the multimeter in the 12 volt ( or greater) DC mode.>>>Dan

 

[John From Detroit]

Motor home or trailer???? on a motor home I have 2 12 volt factory outlets and a bunch I added. ONE (Factory dash) is a "Chassis" device and fused on one of the two Chassis panels.

The others are all HOUSE with assorted fuses.

Page 2: years ago when they first started making plastic dashes for cars they would occasionally wire the 12 volt lighter socket backwards. Does not matter for a lighter but does for electroincs.

So I built a tester.. I still remember teh schematic

The tester consisted of 3 parts.. a 12 volt plug.. a resistor and a 2 lead 3 color LED.  ( think 470K but not sure on that without looking it up.

The resistor hookd to the center conductor
The LED between the other end of ther resistor and the ground "Bail"

Temp hook up the LED at first and hook to a known proper outlet if the light id RED turn it around

Once a proper outlet shows GREEN solder all connections.

Now RED = Backward, Green = Proper an YELLOW = AC

Back in the 70s  Radio Shack sold the led. alas. Not so sure today.

 

[Henry J Fate]

It very easy to blow the fuse when testing a 12v socket with meter probes. The ground probe is fine as you do not need to insert it very far into the socket if at all. the positive probe must be inserted all the way in the socket to the very center without letting the probe touch the inner sidewall of the socket or you will blow the fuse. To avoid this, place an insulating tube over the positive probe leaving about 1/8 of an inch of the probe exposed at the very tip. This avoids the possibility of a short. I use a piece of shrink tubing which fits quite nicely. Some meters come with a protective add on for this purpose.


If you are sure you have found the correct fuse, take a look inside of the socket to see if it looks clean. I have found some sockets that have spun in the mounting hole causing the wires to be strained or fall off. Most wires attach via plugs. I have also found the plugs off of good mounted sockets. 9 out of 10 times the problem will be the fuse.