Weird electrical problem

ColoradoCamper1 · 09-29-2020, 05:57 AM

We have a 2013 Fuzion 301 toy hauler, bought gently used in 2014. We've used it many times without issue but have strange problems this year, hoping somebody can provide us some insight!

We dry camp. We have 2 new 12 V deep cycle batteries and an Onan 5500 generator. The batteries should charge 3 ways: when the unit is plugged in to shore power, when the Onan is running, and when we're going down the road, from the truck power. It's all worked great until our last trip.

We had the unit plugged in to shore power before we left, and the batteries were fully charged. When we arrived at destination (5 hours) the batteries were noticeably discharged, they hadn't charged from the truck. So we started the Onan, the batteries didn't charge from that either. My husband, boy scout that he is, had a backup generator. We started the Champion 4000 and plugged it into the external power with a 20 amp cord; the batteries still didn't charge. We ended up using trickle chargers powered by the generator to charge the batteries.

So long story short, I'm wondering if this could be a power converter issue? When the Onan or Champion was running the power converter seemed to think it was charging the batteries - solid green light which according to the instruction manual means the batteries are rapidly charging - but no charge (or very little) is actually getting to the batteries.

There is a 20 amp relay that seems to be regulating charge to the batteries. This thing makes an audible click when the Onan is running. If you watch the voltage on the batteries when the relay clicks there is a surge in voltage, then it drops down until the relay clicks again. We talked to Keystone support and they said this is by design, it's kind of a trickle charger. Does anybody have any experience with this thing? Could it be a bad relay?

Long I know but please keep reading, this is the really weird thing. A few things are always on when using just the batteries - the radio, CO detector and the fridge. When you put any extra load on the batteries, say turn on the lights, the lights stay on for about 15 seconds, then ALL power to the unit goes off for about 5 seconds, then everything turns back on. This cycle repeats until we turn off the lights. This seems to happen even when the batteries have a full or nearly full charge. Could this also be a power converter thing?

Sorry, I know this is a lot of information but we're pretty well at wit's end. Can anybody provide us a little help on these issues?

**flybouy** · 09-29-2020, 06:31 AM

From your description I'm guessing the batteries are toast. A battery can have a shorted cell and it will only take a "top charge". The battery will charge to voltage very rapidly and just as rapidly it will die. Remove the batteries and taker them to an auto parts store that can load test them. If one battery is bad then you must replace them both as an old battery will cannibalize a new one.

ColoradoCamper1 · 09-29-2020, 05:01 PM

Well we put in 2 brand new fully charged batteries. still having the same problem. When you turn the lights on, they stay on for a few seconds, then power to the whole unit goes off for 5 seconds or so and the power comes back on. This cycle repeats... Any other thoughts?

**chuckster57** · 09-29-2020, 05:05 PM

Not charging while driving rules out the converter. I’m leaning towards a bad ground.

NH_Bulldog · 09-29-2020, 05:12 PM

I would suggest that you might have a grounding issue at the main connection to the frame at the front. Another thing to check is the automatic circuit breakers up front ( they look like a red Lego block). If there is any corrosion at either location it will prevent a good connection. But a bad ground is my diagnosis.

ColoradoCamper1 · 10-01-2020, 03:52 AM

We checked all connections, no corrosion but we cleaned them up. Still having same issue, lights come on for 10 or 15 seconds, then all power goes off then spontaneously comes back on.
Couldn't find anything that looks like lego blocks. We have a battery cutoff switch inside the unit that cuts off all power to the unit. This seems to be working appropriately.
Does the converter not function to charge the batteries when going down the road? Is there any way to tell if the converter is the problem? I think we could replace it but they're about $500 and I hate to invest that as a stab in the dark.

ChuckS · 10-01-2020, 05:18 AM

To me it appears you have a few issues going on...

... won’t charge from tow vehicle
+++ have you verified with a multi meter on the 7 way plug at tow vehicle that 12 volts DC is present?

... won’t charge batteries with shore power
+++ have you verified the converter is operating with a multi meter?

... transfer switch could also be an issue

To check out converter Id follow the steps in this WFCO troubleshooting link...

https://wfcoelectronics.com/wp-conte...800-Series.pdf

Note..

Converter has nothing to do with charging batteries while towing down the road...

I’d also do a specific gravity test or load test,on those batteries...

Disconnect batteries and test converter first to at least eliminate converter issues... you can power fifth wheel without batteries and run off converter till issues are isolated

And the off and on issue with DC power sure sounds like a resettable DC breaker opening and closing due to either a short, loose connection, or defective DC auto reset breaker ..

Or transfer switch issue

**flybouy** · 10-01-2020, 06:15 AM

Quote:

Originally Posted by ColoradoCamper1

We checked all connections, no corrosion but we cleaned them up. Still having same issue, lights come on for 10 or 15 seconds, then all power goes off then spontaneously comes back on.
Couldn't find anything that looks like lego blocks. We have a battery cutoff switch inside the unit that cuts off all power to the unit. This seems to be working appropriately.
Does the converter not function to charge the batteries when going down the road? Is there any way to tell if the converter is the problem? I think we could replace it but they're about $500 and I hate to invest that as a stab in the dark.

As has been previously stated a couple of times the converter is a device that operates on 120v ac. As you are driving down the road you are not connected to 120v ac. The truck may or may not provide 12v DC to the camper thru the 7 pin plug. It depends if it's wired or not. That you would have to confirm.

The batteries....Are they connected correctly? Two 6v batteries would be wired in series and two 12v would be connected in parallel. Incorrectly wireing the batteries can damage the batteries and the other equipment in the trailer. Although rare, you can get a new battery that's bad.

The auto resetting circuit breaker that "looks like a Lego block"...... It's there, you just didn't find it. Trace visually and with your hands the positive wire from the battery to where it enters the camper (not just the pass thru). If that wire goes directly to the cutoff switch then continue following it after it leaves the cut off switch. You WILL find it.

Testing ..... From your responses I don't see where you have actually tested anything. If you don't own a VOM (Volt, Ohm, Meter) or commonly referred to as a multimeter then get one and learn how to use it. A simple meter can be purchased for well under $20 at any big box store. You will need it at some time in the future and can save you a lot of money once you know how to use it and interpret what the reading from the meter is telling you. Without it, you are simply guessing as you cannot "see" the flow of electricity without it. It's like kicking a tire and saying it's ok.

ColoradoCamper1 · 10-24-2020, 02:20 PM

Thanks everybody that replied. Took us awhile but we learned a lot. Really, really a lot. I'm going to put the solution here in case anybody is researching a similar problem.

Problem was the power was cycling on and off, and the batteries weren't charging from the truck, the generator or at the end when plugged into the shore power.

Turns out it was the automatic circuit breaker (thanks NH Bulldog, yes looks just like a red lego block). There was 1 20 A breaker. We think that one of the slide motors is starting to go bad and was consistently drawing more than 20 A, causing this thing to break, so the whole unit electricity shut off. It resets but I guess over time it takes less draw for it to fail. We ended up separating out the slide from the rest of the unit and put 1 30 A breaker on the slide, another 30 A breaker on the rest of the unit. So far so good, everything is working better than it has in probably a year, and everything is charging.

One more (probably stupid) question. There is a test panel inside the unit. It shows fresh water, gray water and black water levels and also shows battery capacity in the form of 4 lights. The lights are labeled C, G, F, L with "C" being 4 lights. OK so I get L = Low (1 light). F = fair? G = good? Somebody told us that C = chargING. That was when we were having problems, and the 4th light would illuminate when the generator was running, implying that the batteries were charging, but would quickly drop down to the 3rd light. Now the 4th light is consistently lit, batteries are new and fully charged and I'm wondering if C = Complete? ChargED? The Keystone owner manual is pretty lame and doesn't address this.

**chuckster57** · 10-24-2020, 03:19 PM

It will show 4 lights when charging and for a short time after due to "surface charge". turn on a few lights and it probably goes to 3 lights and will stay there for a while. Its NOT really a good indication of the batteries state of charge. There are several different products you can use to get a much more accurate assessment of the batteries.

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