DC power question

mikegascon1 · 03-14-2022, 12:13 AM

I just purchased a, new to me, 2007 3124. I believe it is a KB maybe. It has a couch on one side and a comfy chair on the other side of the table. Is that a KB?

First major question is DC. When I looked at the trailer, it was on shore power and everything worked fine. Today, I was preparing to fold it down in anticipation of getting new tires tomorrow. I removed shore power and found that I have no power anywhere that I can find except the electric jack. I checked multiple lights, both inside and out. I checked the water pump and even the display with lights for fresh water, grey water and battery level. No lights on any of the panel. I did check the breakers and they were all on the "on" position. The weather was turning bad and so I did not check the fuses yet. I did test the battery with presumably no load and it read 11.1. I assume that means dead battery. But again, the jack works. It does go slowly and really works but I just assumed it was a tired electric jack. If it can power the jack, wouldn't the lights come on for the panel with water levels? I also checked the water level in the battery and it looked fine. After I hooked the 7 pin plug to my truck, I noticed an outside light came on. That makes me believe my truck was essentially powering that light. I do not know the age or even brand or style of battery.
After I open it back up and leave the truck connected, if the lights work, can I assume the battery just needs to be replaced? I will check fuses also. Is there a fuse for the converter? I did not notice one but it was fairly dark in the trailer. Is the converter built in or around the breakers? I have read where people have upgraded their converter and I dont even know where mine would be.
Also of note, I did confirm the pin in the wall of the bathroom was depressed as it should be for lights to work.

Lastly, for tonight at least, my model is a 3124 KB (I think). On the rear, just above the bumper is an outside access panel. It is unusable until the rear bed slides out. The door is approx 2.5 ft X 2 ft and the box is approx 1.5ft deep. Is that just a storage area? I ask because I do see a small wire bundle in there. The wires are not accessible from the inside that I can see at least. If it is for storage, it is too bad because I cant get to it until the back is up. I was thinking of misc leveling products or towing devices could go in there but that wont work out.

I think the DC will be easily solved. It will help once I get new tires and can open it back up at home again and hopefully the weather in the PNW will dry up some. I am so excited for this and to be part of this family.

Thanks in advance.

**Bill** · 03-14-2022, 03:43 PM

Mike -

All of the power from (or to, meaning charging) the battery flows through the 30-amp main fuse, which is located in the wire connected to the positive battery post, and maybe 6 inches or a foot from the post. Start by checking this fuse.

Depending on the make/model of your converter box, power then may flow through another main fuse in the box, before being distributed to the fuse panel and the various 12-volt loads. It is unlikely that all of the fuses in the panel are bad, but it is possible that the main fuse in the box is bad. The fact that everything works on shore power says this is unlikely, but it is worth checking. You probably have (or should download from the mfr's web site) a copy of the manual for the converter. This will tell you where the internal fuses are located.

So how come the electric jack can work, you ask? The jack is an aftermarket add-on. My guess is that whoever installed it brought the power wire directly to the positive battery post, bypassing the 30-amp main fuse and the fuses in the converter. If you have two wires attached to the battery positive post, the extra one probably goes to the jack.

The fact that the battery reads only 11.2 volts means that it is not getting charged. No need to replace it (yet, anyway). Again, if the 30-amp main fuse is blown, no charge current will make it to the battery. And depending on the arrangement of fuses in the converter, a blown fuse there could have the same effect, though as I say, this is less likely.

Let us know what you find.

Bill

**Bill** · 03-14-2022, 04:17 PM

Quote:

Originally Posted by mikegascon1

Lastly, for tonight at least, my model is a 3124 KB (I think). On the rear, just above the bumper is an outside access panel. It is unusable until the rear bed slides out. The door is approx 2.5 ft X 2 ft and the box is approx 1.5ft deep. Is that just a storage area? I ask because I do see a small wire bundle in there. The wires are not accessible from the inside that I can see at least. If it is for storage, it is too bad because I cant get to it until the back is up. I was thinking of misc leveling products or towing devices could go in there but that wont work out.

Mike -

You've got a pretty good mental picture of that compartment. Yes, it is for storage. No, you can't open it until the bed is out, and no, it is not accessible from inside. In some models, the battery is in that compartment. On other models, the battery is on the tongue up front. If you have a KB, then I think your battery is up front. I use the compartment to store things that I won't need until the TM is parked and open - mostly the utility hookup stuff (except the sewer hose). I installed hooks on the walls, and I hang coiled up water hoses (one short, one long), coiled up extension for the main power cord, a 50-foot 14-gauge 120-volt extension cord, cable TV cords (again, short and long), power adapters, and so forth. I also keep two tool boxes in there, one with electrical tools and supplies, one with mechanical tools. When I added solar to one of my earlier TMs, I mounted the solar controller, fuses, and connection block on the wall in there. You can make good use of this space. Incidentally, I installed a 12-volt fluorescent light in there - it is dark.

I keep a plastic milk crate in the truck for all the stuff needed for setup, and for roadside work. Chocks, lug wrench, bottle jack, small 12 volt compressor, spray can of silicone lube, tube of lithium white grease, can of 3-in-one oil, roll of duct tape, roll of paper towels, tongue jack pad and wheel, leveling boards - you get the idea. Although I don't do it, some of this stuff could be carried in the two small compartments at the ends of the bumper. The cover of this compartment can come off without raising the rear shell.

As for the wires in the compartment, I'm not sure, unless the extra wire goes to your electric jack. The only ones I would expect to see are the red/black wire to the positive battery post, and the white/green/bare wires to the negative battery post. In my newer 2020 TM, all the wires for the optional solar setup are bundled up in there, but I'm not sure that was true in earlier years.

Hope this helps.

Bill

mikegascon1 · 03-14-2022, 04:46 PM

I did discover today that at least one interor light work when connected to the truck. I accidentally left that light on yesterday. Today as I opened it up for new tires, I saw the light was on. I also pushed the test button on the fresh/Grey water panel and it works. Does that mean ir prove anything? I have nit had a chance to find the Fuse close to the battery yet.

Thanks for the excellent ideas for using the rear compartment. I will do similar as you said. Love the adding of a light in there idea.

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**jagizzi** · 03-15-2022, 08:27 AM

Hi Mike,

Glad you found a trailer and are getting it going. Should make fire season a bit more comfortable and if history is any teacher we in the PNW want our wildland folks safe and comfortable! ;-)

I'll ask the obvious first, did you fold down the bathroom walls before you pulled power? Power for the rear shell, which has most all of the lights, runs through a switch that is opened when you fold the bathroom walls. This would keep your lights from working but allow the tongue jack to operate.

Given the age of your TM, even though it is newer than mine ;-), you are going to want to make sure that battery cables and connectors are up to the task. It is amazing what shows up as user modifications for battery cables and lugs. Mine were a fire waiting to happen. I also chose to install a disconnect switch and a breaker rather than the fuse for the battery feed as it gives me better control.

Good luck with the discoveries and trailer.

Jim

**rickst29** · 03-15-2022, 10:33 AM

Quote:

Originally Posted by mikegascon1

First major question is DC.... I did test the battery with presumably no load and it read 11.1. I assume that means dead battery. But again, the jack works. It does go slowly and really works, but I just assumed it was a tired electric jack. If it can power the jack, wouldn't the lights come on for the panel with water levels? I also checked the water level in the battery and it looked fine. After I hooked the 7 pin plug to my truck, I noticed an outside light came on. That makes me believe my truck was essentially powering that light. I do not know the age or even brand or style of battery.
After I open it back up and leave the truck connected, if the lights work, can I assume the battery just needs to be replaced? I will check fuses also. Is there a fuse for the converter? I did not notice one but it was fairly dark in the trailer. Is the converter built in or around the breakers? I have read where people have upgraded their converter and I dont even know where mine would be.
Also of note, I did confirm the pin in the wall of the bathroom was depressed as it should be for lights to work.

11.1 Volts on a lead-acid battery with no load indicates the battery to be at nearly zero state of charge and probably ruined. It was likely left unplugged with "phantom loads" consuming power, and no battery maintainer device to keep it charged. New batteries.

If your model year is 2007, then the "Load Center" was made by WFCO and the power converter "main board assembly" is in the bottom half. Since everything works while you have it plugged in, the MBA is not completely shot - but WFCO Converters from those years basically quit when the battery reaches around 85% charged. Lead-Acid batteries should be stored as close to 100% as you can reach without overcharging, and kept there for the maximum possible amount of time. For about $170, you could replace the converter section with a more modern and somewhat better replacement (another WFCO "MBA", or a "Boondocker"). For $250, you could switch to American made unit which I have - the "WildKat", a somewhat modified Progressive Dynamics Converter. It's just about perfect for lead acid batteries, including AGM and GEL types. But it's "Lithium" setting tries to keep Lithium batteries at 100% State-of-Charge all the time, which is great for lead-acid but a bad idea for Lithium. I have Lithium batteries, and get great results by using the "AGM"/GEL" charge settings. (Batteries rest around 93% State-of-Charge, which I can crank up by using the pendant to force "Boost Mode" whenever I want to push them higher). Victron Energy makes even better power converts than the Wildkat, and they have remote monitor capability - but they're more expensive and will not fit inside the WFCO assembly cabinet. Here's the link to buy the WildKat: https://www.bestconverter.com/PD-465...te-_p_677.html

One common issue with TM trailers of that age occurs with the safety fuse within the battery box. A small glass fuse fits inside a plastic case, which uses a spring to hold the fuse somewhat tight. Over time, that spring often rusts and creates high resistance. I recommend that you replace that fuse with one of these. It's NOT waterproof, and needs to go inside the battery box (connecting to the wire which leads to the WFCO power center DC fuse board). Use the 30A fuse, unless you upgrade the TM wire size to 8-AWG or larger (then you could use the 40A fuse): https://www.amazon.com/Febrytold-Gau...dp/B08QHKXD5N/

JohnMD · 03-15-2022, 06:11 PM

Last year, when we bought our used Trailmanor, the existing battery was dead. I bought a new battery and installed it, only to find that I had no DC power. After inspecting things, I noticed a lot of corrosion on the battery wire ring terminals. After some light sanding, I reconnected the battery wires and everything was fine. Perhaps it could be something that simple (presuming you have charged the battery)?

John

mikegascon1 · 03-15-2022, 07:07 PM

It was the 30 amp Fuse by the battery. After the weather gers better, I will replace the Fuse and continue learning the one and outs of things. I just received my interior LED lights so those will go in right away.

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mikegascon1 · 03-19-2022, 07:08 PM

On my lat post, I said the 30 amp Fuse in line with the battery was blown. I replaced the Fuse and it blew again, immediately. I was also on shire power. I assume that means a short, but where do I start? Where the wires go in, under the bathroom?
Unrelated but not good, is there are wires that were zip tied to the axel. I assume trailer brakes. I noticed tonight that all zip ties were gone. It must have happened when I got new tires last week when I was driving. Would it have applied brakes if those wires were ripped off? I did test the brakes as I left the house and they worked. I believe they worked the entire trip. I tow with a Ram 1500 so I have the brakes fairly soft.

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**Bill** · 03-19-2022, 10:39 PM

The wires zip-tied to the axle actually carry power to the magnets in the brakes, so if they are broken, the trailer brakes won't work. Or more likely, the right brake won't work (since its cross-trailer feed wire is broken) but the left brake will work as it should. Not a good situation, of course, since the trailer will try to swerve as you apply the brakes.

You should get some nice long zip ties, and re-tie the wires to the rear face of the axle, where they won't be hit by anything on the road.

Bill