Greetings! I've been on Ford-Trucks.com and only recently scrolled far enough down the forum list to see this little gem of a group, so maybe you guys can help me out a bit.

I volunteer with a search and rescue team with our local FD, and we have 5 16' dual axle Mirage trailers. Each has surge brakes and an on-board battery for the interior lighting and two small rear flood lights.

All of our trailers have some kind of short in them that the City mechanics can't find. After burning through two sets of regular car batteries, they decided to add a cutoff switch (on the exterior where the 4 pin trailer adapter sits in a box) and Optima yellowtop batteries.

One trailer gets used probably a minimum of once a month on average. The rest go months (many in some cases) between uses.

They weigh in at just under 7000lbs, and two of them include carts with rehab gear - the carts weigh maybe 700lbs.







So here is what I'm trying to do:
1. I'd like to figure out what size/type of solar panel we could get that we'd be able to plug in (say a waterproof cig lighter adapter, maybe mounted near the cutoff switch). We have covers for the trailers, so the idea would be to fab up a mount on the trailer tongue that would allow it to be outside of the cover to get the sun, but something quickly removed. Ideally weatherproof so we don't have to make runs to remove them before rains.
2. The carts are heavy, and when the trailer tailgate gets dusty or wet, it's downright dangerous to push that cart up (if you slip, you are in serious trouble). We are toying with using a small atv winch to lower the cart down/pull it back up when the weather is bad or the trailer tailgate is dusty. I'd like to connect some quick-disconnects (say 50a Anderson PowerPoles) tied into the battery. The winch would be connected to the floor-mounted e-track with the e-track connectors. The connector would be located somewhere near the door (the cart rests right over the battery box, so no clips to the battery terminals would work).

...finally, if we are going to add in wiring for a winch, why not add in a small power distribution box for radios, charging cell phones, etc. etc.?

So...any tips from you hard-core trailer towers/modders out there?

 

The likelihood of a short in that many identical trailers seems remote. Are you sure the batteries were not simply discharging from sitting so long? Discharge is spontaneous over time so any battery will run down and once completely discharged is essentially dead.

As to solar panel sizing, provided you use the cut-off so there is no drain while the trailers sit, all you will be countering is the spontaneous discharge so even the smallest solar cell should handle that and you could plug it in as you suggest. Lots of folks on FTE do the same thing with their trucks when they don't get regular use. Mounted on the tongue, you will have to be conscious of how the sun hits the trailer so the panel is not shaded.

There are dozens of ways to mount a winch. I would simply suggest going with what is the easiest for you. For the load you are suggesting, it is not going to take much of a winch. I keep one around I picked up at Northern Tool, but I don't mount it permanently, just fasten it where I need it and use my battery booster for a supply. Not elegant, but has worked for years. Not fastening anywhere permanently, I have it where I need it, when I need it.

Distribution panel for power, lots of choices. Be sure to check the draw of the winch if you want to run it through the panel. Other than that, it is simply how many circuits you need. You can also make your own panel pretty easily for flexibility, if you can not find what you want.

This sounds to me like one of those projects where there is really no right or wrong. It will likely boil down to how elegant you want to make it, how much you have to spend, and how much time you have to invest in the project.

Steve

 

The City mechanics identified a ground short, they just couldn't find it. We put in a brand new battery in the trailer I primarily pull and within 3 months it was dead.

 

Just a curiosity. Must be a very small short to ground to not blow a fuse, chafed wire or something similar I am guessing.

Steve

 

We suspect the same...maybe something pinched between a panel and the frame, etc. Would make more sense as to how it came to be across all 5 trailers. Some are affected "worse" than others, so a crushed wire seems likely.

 

sounds like a rewire job to me. Not too difficult on that type of a trailer.

 

How are you recharging the battery? If it is a 4 pin connector you must have shore power or something to charge it, correct?

 

No, 7 pin. It does have a 4 pin adapter in a box on the tongue.

 

Have you checked the battery voltage with the truck hooked up and idling?

 

I would have assumed the City did that part. We had put in one completely new battery fully charged when the first one was discovered dead. One trip - from the corp yard to the firehouse, then it sat. Something like 2 or 3 months later it was dead.

They dropped in an Optima at the firehouse for another trailer - again fully charged...trailer had not been towed...battery was dead on that one maybe 4 months later.

I know it's not my particular truck - I was able to 'recharge' one of the early batteries on a trip from Sacramento to Fresno for training, and a test of my output on the umbilical connector at my hitch was all good.

 

I would be curious what the current draw is when the thing is sitting still. There should be none if you have the lights off.

 

I share your line of thinking, but do not think that is the issue in this case.

Steve

 

I don't think it is a ground fault if it is doing the same thing on all of the trailers. Seems too coincidental, no?

 

Seems like it has been dealt with. The disconnects will do the job regardless of the cause. Toner and a meter should have nailed it.

 

time for process of elimination