Hi all, I have a 12v battery on my small sailboat which primarily powers navigation and interior lights. There is a cigarette lighter style input on the fuse panel which works well when I plug in a spotlight and a fan connector. However, anytime I have tried to plug in a USB phone charger it won't work at all. It blew one of them up I think. Why would this be? How might I fix this. The boat may be 30 years old but is new to me. Thanks in advance!

 

Is the socket wired with reverse polarity as in being a postive ground not negative ground?

 

Have you got a voltmeter to test the polarity of the socket?

 

Is the socket wired with reverse polarity as in being a postive ground not negative ground?

The center pin should be the positive one... At least for the USB device..

 

Is the socket wired with reverse polarity as in being a postive ground not negative ground?

Thanks I'll try that!

 

The center pin should be the positive one... At least for the USB device..

Thanks. This is a good lead for me to test.