Adding a 12 volt power adapter

Parlando

I have a 2015 320 T@B.  I would like to add one or two 12 volt cigarette style power adapter in the back of the cabin.  Can I tap into either the audio speaker for the radio or the small reading light? 

Grumpy_G

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. 

Parlando

@Grumpy_G    Thank you.  I want to use it to power a 5 volt fan or charge iPad.  I'm curious, can you explain why the light will work, but not the speaker?  I'm still learning about electrical processes.  Thanks

MuttonChops

@Parlando ;  What @Grumpy_G said . . 2X

Your 2015 wring should be about the same as the 2016.  The Rear Reading Lights are connected to a 10-Amp Fuse at the Power Center Fuse Panel.

Reference:

P.S.  Speaker wires are low voltage 'signal wires' not Power Sources.

Parlando

@MuttonChops   Thank you.  2 Questions: So I won't overload that 10Amp fuse?  And what size wire should I use to connect to the new power adapter.  Also... hello Mutton Chops.  We met you at Lincoln Rock state park last year.

Grumpy_G

The speaker wires don't carry 12V DC but amplified audio signals (high frequency AC if you will) from the radio. 

MuttonChops

Parlando said:
. . .  overload that 10Amp fuse?
. . .  what size wire should I use to connect to the new power adapter.

For what you are planning to use the additional 12VDC outlets for . . . most likely the 10-Amp Fuse will be fine.  Of course it never hurts to be cautious at first and don't turn-on everything connected to Fuse-3 while using the 12VDC outlet.

I would use a wire size about the same or slightly larger than what you find on the reading light (source / feed side {coming from the Power Center}).  Using a bigger wire at the 12VDC outlet won't help anything as the Wire from the Power Center is the important one.

Parlando said:
. . . We met you at Lincoln Rock state park last year.

Yes indeed.  You were the newbie's on Loop A.  That was a good East-Meets-West.

Parlando

@Grumpy_G and @MuttonChops.   Thanks again. Great support and advice. 

Parlando

Okay, I hit a snag.  I used Wago wire connectors to tap into the wires for the LED light in the back. Everything looked proper but I blow a fuse everytime I put an USB adapter into the 12 volt cigarette style power outlet. This is the 2nd of two usb outlets I got from Amazon, and the first is working fine.  I checked power at the wire connectors going into the back of the power adapter and got 12.5 plus.  I checked the power adapter plugged in and got the same reading.  I made sure that I had the positive wire of the LED light tapped into for the positive wire of the adapter, and same for the ground.  So I am confused what I've done to cause a fuse to blow. The only thing on when I was blowing the fuse was the lights and the CO2 detector.  Just one light. Any thoughts?

Parlando

@Sharon_is_SAM  Hi Sharon,  I just noticed that somehow I listed this under For Sale, obviously the wrong place. Is there a way to move the thread?  -Doug

Parlando

@MuttonChops @Grumpy_G Okay, I hit a snag.  I used Wago wire connectors to tap into the wires for the LED light in the back. Everything looked proper but I blow a fuse everytime I put an USB adapter into the 12 volt cigarette style power outlet. This is the 2nd of two usb outlets I got from Amazon, and the first is working fine.  I checked power at the wire connectors going into the back of the power adapter and got 12.5 plus.  I checked the power adapter plugged in and got the same reading.  I made sure that I had the positive wire of the LED light tapped into for the positive wire of the adapter, and same for the ground.  So I am confused what I've done to cause a fuse to blow. The only thing on when I was blowing the fuse was the lights and the CO2 detector.  Just one light. Any thoughts?

Grumpy_G

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 one is confirm that the center contact deep in the socket is indeed positive. 

Parlando

@Grumpy_G   Thanks I’ll check it out

Mickerly

My 2018 has double outlets with one side USB and one side 12v. The replacements at eTrailer.com are the same brand and model as I have from the factory.

Parlando

Well, I think that I finally figured it out. After buying a new and more expensive 12V outlet, and then putting in the USB adapter, the fuse blew again.  Finally, out of options, I attached the red wire to the negative side of the outlet, and the black wire to the positive side of the outlet, and everything worked perfectly. So I think that they accidentally switched the positive and negative wires when they wired the LED light. ???

MuttonChops

Never Trust the Wire Jacket Color.
Always Verify With a Meter or Tracing the Wire Path end-2-end. 

Parlando

@MuttonChops I appreciate that and I tried looking up how to do that on YouTube. I found one method that would work with my meter, but required finding a ground to use, which didn’t find inside the wooden cabinet. So I finally took a guess and made the switch, which luckily worked. I’ll have to see if I can find someone who can show me how to use my meter To verify. Thanks MC!

AnOldUR

@Parlando I believe that if you put the positive lead from your meter against the connection at the center/bottom of the cigarette port and the negitive lead on the outer edge you should get a positive 12V reading. If the wires are reversed it will show as negitive 12V.

MuttonChops

@Parlando;  You might look for a Book like this one:
    The 12 Volt Doctor's Practical Handbook
      'for the boats electric system'
       by Edger J Beyn

                          Amazon Reference

Or a similar publication that starts with the basics using simple descriptions and examples for a variety of DCV applications on a boat or RV.

For your recent Mystery Wires: