Brake lights out

[Route66]

1st camping of the season and we discovered that our Fun Finder Shadow Cruiser had no brake lights and now rear turn signals operating. Later that night at the campground the interior lights were extremely dim and barely operating. I remembered that I recharged the battery at the end of last season but it was also a 2013 year old battery and not sure if it held the charge. Could this be the reason for the brake light and rear turn signal lights not working? Please help. Thank you.

[APD]

The trailer brake and turn signals are powered from the tow vehicle.
The interior lights would be powered by either the camper battery or the converter if you are connected to shore power while camping.
The one thing the items have in common is the ground (negative) connection on the 12 volt side. I would trouble shoot the battery connections and the 12 volt converter connections.
You may have a poor connection at the trailer plug and a poor connection at the trailer battery as well so cleaning and checking all connections would be a good start.

[SWFL FlyFisher]

I'm not completely up on FF's 12v systems yet, but from previous experiences I agree with APD. Its not likely that you developed two different (but related) issues at the same time, so I'd investigate those components that the two 12v systems share.

[Route66]

I just recharged my battery in the Fun Finder Shadow Cruiser and all interior light and the exterior brake light and turn signal light are ALL working great. Thank you all for you assistance.

[DiverRick]

Originally Posted by Route66

I just recharged my battery in the Fun Finder Shadow Cruiser and all interior light and the exterior brake light and turn signal light are ALL working great. Thank you all for you assistance.

The trailer battery being charged has nothing to do with the trailer brake lights. (or they shouldn't) Although a **really** poor trailer battery, could be sucking all the juice before it gets back to the trailer lights.

When you activate your brakes from the tow vehicle, the power from your vehicle is sent all the way back to your trailer's brake lights, nothing to do with the trailer battery. Same with turn signals.

I suspect there's something wrong in the wiring harness connections between you towing vehicle and trailer. Easily tested.

There's something else at play here.

PS: Your trailer's battery should be getting charged up when attached to your towing vehicle or when plugged into power at your campsite. You shouldn't be having to re-charge it all the time, when it should be charging while driving, or when detached and set up (if plugged in).

[Route66]

How do I check the wiring harness connection? As of today all interior and exterior lights including brake lights are working properly. But camping this past saturday all were out with a weak camper battery of only 5.68. Thanks for any assistance. Also, the brake controller unit is still not working properly. So for now we have just disconnected the unit from under the dash in our Nissan Pathfinder. Is any of this related?

[DiverRick]

Originally Posted by Route66

How do I check the wiring harness connection? As of today all interior and exterior lights including brake lights are working properly. But camping this past saturday all were out with a weak camper battery of only 5.68. Thanks for any assistance. Also, the brake controller unit is still not working properly. So for now we have just disconnected the unit from under the dash in our Nissan Pathfinder. Is any of this related?

- I bought one like this to quickly test the OUTPUT of my truck's connection: https://www.amazon.com/58270-7-Way-B...+wiring+tester If everything checks ok, then your problem(s) are on the trailer side of things.

- I take it you are not plugged into any power last Saturday? If you are running 100% off the battery over a weekend, then you can easily run down a battery if not being careful. Either way, that battery may be shot, and getting a new one will help figure out where your problem(s) are.

- I'm not sure why you'd say you don't have any brake lights while camping, once disconnected from your truck, you SHOULDN"T have any brake lights on!

- You don't want to drive too much without that brake controller working!

- All of these issues are VERY hard to comment on without knowing what your power source is when things are not right.

Are you A) Connected to your truck, B) Connected to shore power (30amp/110v) or C) DISconnected from your truck & with no 110v, and running 100% off your trailer battery. Which of these three really matters.

[APD]

The trailer brakes are electric and powered from your tow vehicle as well. I suspect you have wiring issues. It could simply be a poor connector or broken wire.
First things first:
Check your tow vehicle/trailer connections first (or have a tech do it) and get that repaired.