Hmm that certainly becomes interesting... I think the likelihood that you got two defective jacks is very small. Can you bench test the jack with a jumper pack or similar power source ? These things … (View Post)
The trailer frame may not have connection to 12V ground. If you have jumper cables connect the battery negative to a shiny bolt on the frame and see if it works then. (View Post)
A number of possible causes: The USB adapter is defective, the 12V socket is not wired correctly or either one is designed so badly that it causes a short when plugging in (yes I've seen that). Step … (View Post)
No, it doesn't matter if the 12V supply comes from the converter or a battery. Given that the interior lights work at least part of the 12V system is working. Next step would be to check the DC fuse … (View Post)
Not the speaker but the reading light will work. However the wire gauge might only allow for lower power 12V devices, no inverters or similar. (View Post)