No 12v on battery

[walker77]

I have a 2002 25ft classic that I cant get the 12v to work on the batteries (has 4). Its also not charging the batteries when its hooked up to 110v. Things like the electric jack and lights only work when its plugged into 110v. And nothing works when its plugged into the truck.


The trailer has 4 solar panels on the roof. We are the 3rd owners so I dont really know much about those. But they aren't charging the batteries either.


I put a new inverter in it last fall thinking that was the problem but it didnt fix anything.


Any thoughts?

[Al and Missy]

With the wiring changes for solar, there are a lot of possibilities. Is the trailer new to you? Did it ever work?

First off, did you put in an inverter, or a converter? The converter takes shore power and runs your 12V stuff and charges the batteries. An inverter runs off of the batteries and makes 120V AC so you can run some things that require AC when you don't have shore power.

There should be a battery disconnect switch that reduces current drain from the batteries when opened. I said reduces because some things are wired direct to the batteries. If the solar was installed in accordance with general recommendations there should be a disconnect switch for just the panels. In 2002, at least in my Classic 30, there was a rotary disconnect switch behind the sofa storage drawer. As wired from the factory that switch isolates the trailer loads from everything. They cannot be powered from the tow vehicle, the converter or the batteries. That said, the switch has been wired differently at times and on other trailers. On my 2001 Safari 25 when the switch was off the batteries were isolated but the converter would run the 12V loads.

The solar system charge controller (and battery monitor if there is one) is (are) typically wired direct to the batteries. If so wired the system would charge the batteries regardless of the setting of the battery disconnect switch. But, as I said above, there should be a solar panel disconnect switch, which may be open. Lastly, originally the trailer had self-resetting circuit breakers close to the batteries. My trailer has two. If you have four, the wiring has obviously been changed so all bets are off as to how many breakers there are and where they are located.

What needs to be done is to trace all the wiring which interconnects the TV, the batteries, the DC distribution panel, the converter, the disconnect switches, the solar charge controller, and the inverter (if you have one). If you are not comfortable troubleshooting high current systems and don't have a friend who is, your best bet is to find a good RV electrician who can do it for you.

Al

[walker77]

Sorry, it was a converter. I posted about it here when I first started having issues with it. http://www.airforums.com/forums/f37/...er-183817.html


Im pretty sure we are the 3rd owners. The 2nd owner really didnt use it. Im pretty sure the guy we bought it from said the solar was on it when he bought it.


There is a disconnect switch behind the couch. But its been turned on.

[uncle_bob]

Hi

A voltmeter (even a dirt cheap one from Home Depot) is your friend in this case. The batteries sound like they are disconnected. You either do or do not have continuity ( zero ohms) from the battery negative to the trailer frame. If you don't have a connection there, it needs to get hooked up.

You say you have 4 batteries. Are they 6V or 12V? The trailer came with two so obviously somebody has been busy. What you check next depends a bit on what you have. If they are 6V, you need to check the midpoints to ground. If they are 12V you need to just check the + to ground.

At this point, either you do or don't read voltage on the batteries. If (as you suggest earlier) don't get anything on the battery posts .... they likely are dead. Best bet is they are wet cell batteries and they also have been run dry. ( = check the water levels and top up if needed ).

If you do indeed have zero volts on the batteries, it's not going to hurt to grab a normal charger and see if they will take a charge. It's a pretty good bet that even if they do take a charge, being at zero volts for months and months has destroyed them.

If you have something > 10V on them both with and without the converter charger running, there is a cutoff switch you have not yet found. Tracing the wiring is about the only way to figure out where it might be.

Solar can mess this all up a bit. Best to check things out at night or under cover ( = in the garage).

Assuming it's off to the battery shop, you still need to figure out the charger wiring. Again, if the battery wires don't go to 12V with the converter on (or solar on) there still is a loose wire or disconnect in there someplace.

None of this is outside what a normal RV shop can handle if you want to have somebody else track it down.

Bob

[drbrick]

I agree with all the above - the first thing to do is check to make sure the batteries are not dead with a volt meter, second make sure the batteries are connect correctly, third check to see if there is an inline fuse on either the positive or negative side under the couch. Then follow the advice from above. If all else fails seek professional help.

[uncle_bob]

Hi

Good point about a fuse. The stock setup does not have one (it's a self resetting breaker). That is in no way to say that a modified trailer might not have one. The breakers *do* go bad. They also are not easy to spot unless you know what you are looking at. They look like lugs on a battery distribution block ....

If this *does* head over to "battery(s)" has problems. You need to replace *all* of them at the same time. Mixing and matching 4 batteries of different ages / brands / types is *not* a good idea. Yes, with 4 batteries this is expensive. If whoever put the system in did not do it with all "same size" batteries ..... time for a redesign.

Regardless of what the basic problem is, you need to *know* how your trailer is wired. Getting a used / heavily modified trailer with a "mumble mumble mumble ..." description of what's where is not a good thing. Being well past the original guy who did the work likely rules out a phone call to get clarification.

The only real answer is to trace it all out and document what goes where. This is *not* the last problem you will ever have. Next time may be out 50 miles from nowhere with no cell coverage. That's not the time to start wondering where this and that is..... Either trace it all out yourself or have somebody do it for you.

Bob