12-Volt Outlet Charging Woes

[Dean Abramson]

Thanks everyone. Here is an update.

I am in business now.

I think the Polarity Contingent had it nailed. I believe that this is what happened: I tried the two chargers in the original outlet, and, immediately, reverse polarity killed them off. When I installed the new outlets, I got the polarity right, but I kept testing them with devices that were already dead and gone! Basically, the problem was fixed as soon as I installed the first of the two replacement outlets. I was just too dumb to realize it. I did not need to move on to the third outlet. Anyway, all is well.

I got a charge out of this discussion.

Dean

[M. R. Bober]

...

Touch your volt meter leads to a battery and then reverse them and you'll see 12+ volts either way, same with a cigarette lighter.

Actually, my meter--and probably yours--reads -12VDC when the leads are reversed.


Mitchell Bober
Sunny Lancaster (where we are currently positive,) VA

[Maine Sail]

...

Touch your volt meter leads to a battery and then reverse them and you'll see 12+ volts either way, same with a cigarette lighter.

Actually, my meter--and probably yours--reads -12VDC when the leads are reversed.


Mitchell Bober
Sunny Lancaster (where we are currently positive,) VA

Exactly!! This is why one lead must go to a separate ground circuit, like the ground buss or battery post, and NOT directly to the ground of the lighter socket.

This way you can confirm if the sockets housing/ground is actually hot or neutral. You could touch the leads to the center-pin and housing all day long, and reverse them all day long, and still get a reading of 12v but still not know polarity.....

[Dean Abramson]

My meter is an analog meter.

But if I touch the red probe to the housing and the black to the center post, it will NOT read 12V. The needle will try to move to the left, beyond zero.

I get the exact same results whether I test just at the socket, or if I touch the black probe to the engine ground.

I don't claim to understand this. (But in any event, my polarity is correct, and my problem fixed now.)

Dean

[Maine Sail]

Some analog meters will read voltage with the probes reversed and some just won't. Most all digital volt meters I've used, and owned, will read it either way. I was assuming you had a DVM not an AVM. Sorry..