jc67

I've got a 10yr old sundowner horse trailer and its got a breakaway battery and switch. It looks like the battery gets charged from the brake circuit only, like when the brakes are being used. Seems like it gets only 1 or 2 Volts at any time to charge it. I checked the voltage on the battery expecting it to be at about 12V but its only about 6.8 V. It is a pretty small battery about 4" by 3" and 5" deep. I started wondering if it is just a 6V battery. I should have pulled it right out to see what kind of voltage its supposed to be, but didn't have time. Does this sound right? I have seen other setups where the breakaway battery is a 12V RV, and it gets charged from the 12V charging circuit on the truck. Should I change it around to that setup?

Also, the breakaway switch, can I test that by pulling out the pin, or is it a one time use only? I would like to test the system, maybe 6Volts is enough to stop the trailer in a emergency, especially since it only takes 1 or 2V from the controller. I have been told about disconnecting the plug from the truck first or else it may fry the controller.

1-2-3

It should be a 12 volt battery. What you have is an alarm type battery which is fine for brakeaway backup. i think I've seen them at Tractor Supply in the trailer section, but they had them in the kits, whaich just included a switch. Lowes has them by the home alarms.

The pin on the switch is just that. A pin to keep the contacts apart. When it gets pulled out, the contacts touch and the battery power is sent to the brakes. You should test it occasionally. The battery shgould be getting charged from a dedicated charge line from the truck. most trucks seith a tow package should have the line run allready and might just need a fuse or relay added undewr the hood.

I'm assuming that you have the 7 way round plug. Look at this link for the wiring diagram. http://www.etrailer.com/faq_wiring.aspx

You should have a dedicated hot wire on the center pin of the 7 way round connector.

Totallyrad

I would encourage you NOT to pull the pin. Some trailers do not have a heavy enough wire to carry battery voltage from the break away and you'll make it a one time use only. I would also pull the battery and check it, most likely it's bad. In order to see how much voltage the battery is receiving during a charge, you'll need to disconnect it and then check what's coming in. If the trailer is grounding through the ball, you can get an incorrect reading. Make sure you have a ground wire running through the trailer plug to the tow vehicle's negative post for the best performance of your brakes and lights.

1-2-3

"I would encourage you NOT to pull the pin."

I would consider that bad advice. This setup is there for a reason. if it aint gonna work, what good is it. You do need to pull the pin and test it. it will also help keep corrosion from building up..
Been pulling trailers for 30 years.

Besides, if you take your trailer to a good inspection place, they guy will pull it and test them. If your wiring goes up in smoke, it aint gonna pass. If you take it to most trailer inspection places, they'll look at it and say yea, it's a trailer and collect your $12.50 and put a sticker on it.

Texas law says it must be there and working. You state may differ.

rogerL1961

you should read what it says on the Prodigy site about pulling the pin

http://www.tekonsha.com/instructions...89_H%20web.pdf

jc67

Thanks for the advice, I think I'll have another look at it tonight, I kind of just gently tugged on it before to see if it would pop out easy, but I guess I'll give it a good yank. As long as I can get it back in again.

The 03 in my sig is pulling this trailer, and it has the factory tow harness, a 7 way RV plug. I've got a tekonsha brake controller also. One thing I noticed with the voltmeter, when the trailer plug is not hooked up, and I'm testing voltage on the truck plug, I get 12V on the brake post plus the hot lead post at 12V. When I hook it up to the trailer plug, the light on the controller glows green and then that voltage at the back stops until I activate the controller. That made it a bit confusing at first to figure out which wire at the trailer junction box was the hot lead and which was the brake wire. Couldn't go by wire color without wrecking the nice sealed trailer plug. Far as I could tell that little battery only gets a charge while the brakes are activated. I'll check it again tonight but I don't think I'll mess around with it too much.

1-2-3

The small amount of voltage may be from the controller. I would guess it sends a little bit out to keep tabs on things. My brake controller has flashed codes, and when I looked them up, I found a chart listing problems with my trailer, and it was right, so it's got to be doing some sort of simple testing at all times. Mine knows when there's not a trailer hooked up. Also, your battery can't be charging from just when the brakes are on. There's no predictable amount of time that your brakes might be applied/on. I think you just need to add the charging wire on the center pin.

TreeFarm

Disconnect the trailer from the truck before pulling the pin. Put the pin back in before reconnecting the trailer.

1-2-3

You still need to test it. If your worried about your brake controller, then unplug it before testing. But your really do need to test it before you need it, not use the trailer actually breaking away and heading towards the front of someones house as they are sitting by the window on the couch watching the 6 o'clock news that they are about to be on, to see if it's gonna work.

I have a Drawtite,and my pin got pulled in traffic one time and it didn't hurt the controller one bit. They are bult to handle it.

AlCorr

Mine also got pulled when making a U-turn and there was so much dirt and ice inside it, it wouldn't work, it was stuck (it was winter). I sprayed it out good with WD40 and put the pin back in. Now I pull the pin all the time and spry a electric oil in it.

1-2-3

Spray it with dielectric grease. Also put some on the end of your trailer plug and plug it in a few times. That stuff is worth it's weight in gold. It will elemintae many issues with bad trailer plug contacts. Also put it on your bulbs when you replace them (not halogens), Heck, put it on every single electrical contact and connector on your vehicle and tralier. It's gooood stuff.

jc67

Had another look tonight at it. It's a tekonsha breakaway system. The mini battery is a 12V and I took it out to charge it on the bench. I don't think its accepting a charge so I'll replace it. There is also a RV battery on this trailer for the LQ's so I might try to eliminate the little battery altogether. I should have pointed out that I bought the trailer a month ago and haven't monkeyed with any of the wiring yet and dont really want to. Just checking it out to be safe in case of any emergency.
By the way, I pulled the breakaway pin out, it looks fine, no corrosion and it snapped back in fine too. So once I get the battery charging issue figured out, i can test it for real.
Our last trailer was so old, it only had brakes on the front axle only, and no breakaway system at all. I'm in Alberta, they're not required, last time I checked.

Torqfan84

when testing the breakaway system make sure to pull the 7 flat blade connector then the breakaway pin and give it a tug with the truck be warned it may go a foot or two before the brakes lock up. Had to go through this two weeks ago with 15 fleet trailers for work and every one reacted differently

TreeFarm

The Tekonsha manual specifically says doing so will destroy the controller. They shouldn't be built that way, but that is what it says, so I have not choice but to accept it and never pull the pin when it is hooked up.

Thundercraft

Maybe they are built sufficient well, but you know... just in case.
Could also be a case of Cover Thy Butt