Brake and running lights question please

[rblack22]

If my battery is shot out, which I’m not sure it is, just 5 years old, will it effect my braking and brake lights and running lights? It shows good when hooked to shore power, but drains pretty quickly once shore power is removed. Going to replace the battery regardless, due to age, was just hoping for some good news before I drag the unit to the Arr vee repair place.

[SeaDog]

Put the new battery in and see if all doesn't return to normal

[CHICKDOE]

your trailer brake lights, turn signal lights, and running lights are powered by the tow vehicle. however, the trailer battery is needed to power the brakes if the emergency break away switch gets activated.

[njfishing]

If you have a 7 pin connector and the tow vehicle is wired for it, you might get some power, albeit not much from the battery/alternator in your tow vehicle to the trailer. I will likely run your brake and running lights but you'd have to check to be sure.

Sounds to me like you have a bad battery and if that's the case you should replace it since your emergency run away brake on the trailer will not work without it....

5 years is a lot for a battery so you are on borrowed time and I would bet that's your issue. Simply disconnect it, take it out of your trailer and run it over to an auto parts store and have it load tested and replace it if needed.

You want to make sure you replace it with a good quality deep cycle battery since regular starting batteries like you find in cars are not designed for deep discharge and recharge cycles in RV applications.

Good luck!!

[rblack22]

Thanks everyone, your saying exactly what I was thinking. Ahhh, feel better now [emoji106]

[bedubya]

If I understand correctly, your brake lights and running lights are not functioning correctly. That has NOTHING to do with your trailer's house battery. They are powered through the 7-pin connecter, so that issue is somewhere in the wiring. It could be in your tow vehicle or your trailer. Possibly fuse(s), but not likely since your tow vehicle's brake lights and tail lights are different circuits. A voltmeter and someone to step on the brake pedal will determine if it is your tow vehicle. A length of wire and an ohmmeter will check the trailer. If I did this right, I have attached the 7-pin diagram.

However, as others mentioned, after 5 years, the battery is living on borrowed time.

[rblack22]

Thanks, I took the battery to get it tested, but it was completely dead and they wanted to try to charge it to see if it was bad

[mailman6]

Rv battery has nothing to do with rv tail lights. They run off travel vehicle thru the 7 pin connector. Either bad connection,fuse or relay. Do not know your vehicle type, but ford has a relay fuse under the hood in fuse panel box that runs rv tail lights. Had to replace mine which is rectangle 40 amp relay.

[Scrapper]

Oxidation of the 7-pin connector is a common problem. You'll need to check for corrosion at each pin and clean them with emery cloth. Once done apply a dielectric grease to the terminals. Another cause of problems brake, tail or marker lights is a faulty ground between the TV and trailer. Check the 12v ground connection on the trailer frame for lose or corroded screws.

[PenJoe]

Originally Posted by CHICKDOE

your trailer brake lights, turn signal lights, and running lights are powered by the tow vehicle. however, the trailer battery is needed to power the brakes if the emergency break away switch gets activated.

X2, the house battery is only needed for the break-away switch.

[rblack22]

My apologies for not posting the resolution. Completely forgot till I stumbled across this thread again. Turns out there was a mangled under hood fuse plug that prevented the fuse from contacting, unless I set it in cockeyed and forced connection. I’m guessing the dude I had install my onboard compressor tried this spot and jacked it up, then used a different fuse [emoji35] Got a new fuse box warrantied though, so all good again. As always, thanks y’all [emoji106]