Help! 12v interior light won't work

[Mo22]

Hi all,
for some reason the interior lights won't work. I don't have a battery, just connecting to the hitch wiring.
all exterior light work fine, no issue here.
tracked the 12v interior wires coming from the lights mounted on each side of the cabinet, a black and white wire coming out of each light. blacks are connected together, whites are together.
under the bunk bed I can see the white and black wires. There is also black an white wires coming from the electric compartment, I think they are the fridge 12v wires.

now, all white wires are grouped and connected to the white wire coming from the car. The black wires are grouped, but not connected to anything.

just to test, I connected the black wire to one of the break lights wires, hit the brakes, the lights came on

my question(s)
- I assume the interior lights (and fridge) should work without the car running (or on start), no?
- which hitch wire should the black wires be connected to? which will provide constant power regardless if car lights are on or off.

Thanks,
Mo

[brendadave]

A couple of things to check.

1. when I brought mine home last fall I couldn't get the lights inside to work either, the inline fuse under the front bench, just before it left the trailer was blown.

2. What kind of connector do you have at the end of the trailer wire...4 pin, 6 pin or 7 pin. If it is 4 pin like mine is, that only supplies outside lights, brakes, signals, and side markers.

3. You would need from your tow vehicle a "power line" or "charge line" (it seems to have lots of names). It would be the black wire typically, running directly from the battery. The white wire should also be 12 or 10 gauge all the way from the battery. If you have a 4 pin connector from your vehicle, the thinner gauge wire for the white would not be sufficient for running the fridge, lights would be fine though.

4. If you plan to run your fridge from it while you drive, you would need at least 12 gauge wire (10 is better), all the way from the battery into the trailer where I will guess the 2 wires you see go to the fridge are, those should be 12 gauge wire. My prior owner had uses 16 or 18 gauge wire and you could see that it melted the insulation, the fridge draws too much power for thin wire.

[Mo22]

If you have a 4 pin connector from your vehicle, the thinner gauge wire for the white would not be sufficient for running the fridge, lights would be fine though.

not sure I understand this...
the car has a 4 pin connector, however the trailer 4 pin connector has 5 wires!
which wire would have constant power? or should I just try all of them? there are 2 blacks, only one is used for the trailer exterior lights, the other is cut right of the connector.
I am less concerned with the fridge now.... just want the interior lights to work.

oh, and I don't think there is an inline fuse, should I install one? any particular specs?

[Herb P]

not sure I understand this...
the car has a 4 pin connector, however the trailer 4 pin connector has 5 wires!
which wire would have constant power? or should I just try all of them? there are 2 blacks, only one is used for the trailer exterior lights, the other is cut right of the connector.
I am less concerned with the fridge now.... just want the interior lights to work.

oh, and I don't think there is an inline fuse, should I install one? any particular specs?

The pinout of the 4 pin trailer connector is "GTLR" (Ground, Tail lights, Left, Right). So your fridge only works when you step on the brakes or have the headlights on, depending on which pins the DC supply inside the trailer is connected to.

If you're running your trailer off your tow-vehicle batteries, make sure you carry jumper cables and hope that you're not the last to leave the campground on Sunday night.

If you're the guy who always camps across from me who starts his diesel truck and then goes for a 2 hour hike while his batteries charge, remember that sometimes big orange garbage bags get blown around by the wind and get stuck in front of the radiators of running vehicles which can cause them to overheat.

[Donna D.]

If you're the guy who always camps across from me who starts his diesel truck and then goes for a 2 hour hike while his batteries charge, remember that sometimes big orange garbage bags get blown around by the wind and get stuck in front of the radiators of running vehicles which can cause them to overheat.

Or a potato up the tailpipe which also causes the vehicle to shut down and it takes HOURS for a mechanic to find the potato...cause they don't know that's the problem.

I'd hookup to shore power (if you can) and track the problem from there. You more than likly won't be hooked up to the tug when you want the interior lights to work.....

Ground????

[Mo22]

Ha!
I get it now (I think).
so I guess I need a deep-cycle battery to power the interior lights (no fridge).

I will do more research to find out my options (which battery) and how to install it.

Thanks
Mo

[brendadave]

not sure I understand this...
the car has a 4 pin connector, however the trailer 4 pin connector has 5 wires!
which wire would have constant power? just want the interior lights to work.

My guess from your description, you don't have a "power line" from the car. If I read your description right, the second black wire is not part of the connector? If that is correct, your prior owner may have run some sort of wire from the tow vehicle battery to give power to the inside lights...who knows for sure.

Another option, if you only have 3 inside lights like I do, and that is all you want to power is those lights, you could pick up a 300 amp "jump start" battery (I have seen them as low as $20 at Candian Tire), then all you need to do is add a male cigarette lighter adaptor to your trailer and plug in the battery. When you travel in your car it usually includes an adaptor to plug into your car to charge while you are driving. It would be the cheapest and easiest way to go. If you add a deep cycle battery you still have to have a way to charge it.

[Mo22]

you are correct. there is no "power line" from the car.

so I went shopping

picked up a deep cycle battery from Can Tire and also a 5.5 amps solar pannel to tricle charge it, it was on discount for $50.
installed the battery in a battery box under the bunk and connected the interior lights.

all works good!

I need to find out now why the flurescent light won't work..... but that should be relatively easy.

Cheers,
Mo

[Herb P]

picked up a deep cycle battery from Can Tire and also a 5.5 amps solar pannel to tricle charge it, it was on discount for $50.
installed the battery in a battery box under the bunk and connected the interior lights.
I need to find out now why the flurescent light won't work..... but that should be relatively easy.

(1) 5.5A or 5.5W? Probably 5W given the price.

(2) If that's not a gel cell, you might want to provide a bit of ventilation if you're putting any significant amount of current into that battery at any point... Your solar panel won't cause enough of any gas to cause problems. But if you charge it at 30A from your car, then you may want to leave the bunk open and possibly a roof vent. Hydrogen is much lighter than air.

(3) The flourescent fixture might be 110VAC and require "shore power".

[Mo22]

sorry, yes, 5.5w
Anywho, I am happy with the current setup.

will the battery charge automatically once the solar pannel is attached to it?

[Herb P]

sorry, yes, 5.5w
Anywho, I am happy with the current setup.

will the battery charge automatically once the solar pannel is attached to it?

You should consider putting a charge controller on it but with a 5.5w panel, you may not need one. not sure.

[Gina D.]

Charge controllers are generally not required for anything under 15 watts, but it does not hurt to have one there.

A 5 watt panel will not do much more than keep your battery topped off. It would take days to bring a depleted battery back up to full charge under good sun conditions IF you are not using the battery. In other words.. just sitting at idle.

Those are great for wiring in and leaving attached when the trailer is in storage for a long time and maintaining the full charge.. if the trailer is parked with a full charge. I have a little 7 watt job for just this.. it sticks to the inside of a window and is plugged into one of my 12v outlets, bypassing the controller and I have had no ill effects. The little panel I have for that was designed for VW and they install them in all new vehicles to keep the battery charged during shipping and when on the dealers lots.

If you are planning on daily charging while out in the wilds, you want to consider a more substantial set up.

I ran off of a mere 15 watts for a long time, but I had to be conservative with my electrical usage. That was in my 13. I upgraded to a 3 x 15 watts panel array for 45 watts + my old 15 watt briefcase style panels for 60 watts total. In my 17, it seems to have been a good combo. I do not invert stuff, and do not run a lot of high draw items, so I can generally be frivolous with usage and not worry. Weather conditions dictate just HOW frivolous I can be.

More panels are in order, I plan to put another 45 on my roof. I plan to win the lottery too.. but when remains to be seen.

[Mo22]

thanks Gina... all good info.
I will be using the 5.5w to top up the battery... When in the wilderness we are out all day.... just use the lights (flurescent) for an hour or so before going to bed and an nour before heading out in the morning. then it will be charging all day.
hope that does it...

no inverters or other electric equipment... we try to keep it light and authentic :P