Replaced fuses light and 12v sockets still not working

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Replaced fuses light and 12v sockets still not working

Postby rivernstream » Wed Sep 29, 2021 8:24 am

I'm puzzled
I'm not sure what to do next. Some of my circuits are getting power some are not. The ceiling lights are working as is the fantastic fan on my trailer. But the reading lights (one on each side) and all of the usb ports ( all wired on same circuit) are not working. I have replaced the fuses (even though all seemed fine. What's my next step? Unfortunately the builder of my trailer didn't do a wiring diagram so I'm not sure which wires go to what from the fuse box. 167323
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Re: Replaced fuses light and 12v sockets still not working

Postby TimC » Wed Sep 29, 2021 8:35 am

These are just the first steps. You have not given much information so do these steps...

A first step in trouble shooting is to turn on every appliance and then start to pull fuses one at a time. As you unplug the fuses and see what shuts off label each circuit with info about what is on that fuse.

If you pull a fuse and nothing turns off you might be able to assume that this is the lights and USB's circuit.

Do you have a multimeter? Do you know how to check continuity and/or voltage with a multimeter? It is very easy to learn and a multimeter is a very useful tool to have in your camper for these kinds of "emergencies".

After performing the ID of each circuit let us know what you find out. We can help further with more information. One puzzling thing on your photo is a wire comes from the source of power and doesn't output to anywhere. The circuit with a fuse with only one wire. That fuse is doing nothing. Is there a wire tucked up under something that fell off?

Tim
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Re: Replaced fuses light and 12v sockets still not working

Postby tony.latham » Wed Sep 29, 2021 8:42 am

I would suggest getting a 'trouble light".

https://www.amazon.com/Voltage-Continuity-Current-Tester-Indicator/dp/B01BGZ9XRS/ref=sr_1_6?dchild=1&keywords=12+volt+trouble+light&qid=1632926756&s=books&sr=1-6-catcorr

Attach the clip to a ground (-) and touch the probe on any place (+) in the wiring that should have power. That should help you chase this mystery down.

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Re: Replaced fuses light and 12v sockets still not working

Postby rivernstream » Wed Sep 29, 2021 6:02 pm

Trailer has the following "appliances" on 3 circuits
1 Cabin ceiling LED lamp -- working and fantastic fan both work on the same circuit. These are working.
2. Reading lamps (LED) on either side of the headboard in the cabin. not working
3. USB/12v sockets 2 on each side of interior cabin and one in the galley. not working

TimC wrote: The circuit with a fuse with only one wire. That fuse is doing nothing. Is there a wire tucked up under something that fell off?
Tim
First easy answer...that's just a spare fuse that I put there. I think the builder added a wire from the box to make it easier to add another circuit at some point. I've moved the spare out of the way.

The only circuit that is working is the middle one which runs the lights and the fan.
Since the other 2 circuits don't work I'm assuming that one is the lights and one goes to the usb/12v sockets which are wired inline. I can't label which is which as suggested by the original poster because they aren't working.
I did the test again (i don't have the trouble light or a multi meter but will get one) and labeled the one working circuit. All use a 5 amp fuse, all of the fuses appear to be fine (not blown) and were just replaced (as step one in troubleshooting).

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Re: Replaced fuses light and 12v sockets still not working

Postby pchast » Wed Sep 29, 2021 8:52 pm

Check your grounds... Most usual trouble spot. :thumbsup:

Using a long wire from the battery ground with a test light, prove power at the fuses both sides.
Then pull down the non-working appliance. prove power there.
Then use that long ground wire to see if the appliance works.
If so find a way to repair that existing ground.

You may find connections on the trailer frame that were poorly installed as ground returns.
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Re: Replaced fuses light and 12v sockets still not working

Postby TimC » Thu Sep 30, 2021 10:14 am

Easy thing you can do without testing equipment.

Label all three top wires coming out of the fuse block. Something simple just to ID where they currently are.

Remove the top terminals of all three circuits. You know power is flowing through the middle terminals so connect, one at a time, the non working terminals on the middle circuit and turn on the light/USB appliance.

If you get USBs or reading lights working then the trouble ls before the fuse block. Open up your metal junction box and check that all three black wires leading to the fuse block are firmly wired together. They likely will be wired together with a hot wire from the battery. While in there check the white neutral wires as well. A bad connection inside that white wire connector could also be the problem.

If you still get no power to the reading lights and USBs then the trouble (open circuit) is after the fuse panel. That will require more troubleshooting.

I'm hoping the builder did a poor job connecting the leads inside that metal junction box. That may give you an easy fix.
Last edited by TimC on Thu Sep 30, 2021 10:20 am, edited 1 time in total.
Tim
Niagara, WI
My First Benroy Teardrop Build Thread - A 5x8 Woodie - http://www.tnttt.com/viewtopic.php?f=50&t=63575
My Second Teardrop (partial) Build Thread - Started August '16 - http://www.tnttt.com/viewtopic.php?f=50&t=66939
#3 My son's Benroy Foamie team build - Started July '20 - http://www.tnttt.com/viewtopic.php?f=50&t=72877

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Re: Replaced fuses light and 12v sockets still not working

Postby Socal Tom » Thu Sep 30, 2021 10:18 am

pchast wrote:Check your grounds... Most usual trouble spot. :thumbsup:

Using a long wire from the battery ground with a test light, prove power at the fuses both sides.
Then pull down the non-working appliance. prove power there.
Then use that long ground wire to see if the appliance works.
If so find a way to repair that existing ground.

You may find connections on the trailer frame that were poorly installed as ground returns.

This
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