Intermittent interior 12 volt

[GreyMattr]

Let me start by saying I'm a newb. With that, I just bought a 78 Sovereign 31' center bath that had sat for about 8-10 years. When I bought it (about a week ago), I hooked up a brand new battery and everything 12 volt worked like a charm. Closed it up for the weekend.

Two days later, came to clean/work on it and all the the 12 volt lights/outlets worked except the two bathroom lights. We just figured the bulbs had burned out.

The next day, nothing 12 volt would work. We left it alone for the night.

The next night, all the 12 volt worked again except the bathroom lights. We finished working and left for the evening.

The next day nothing 12 volt would work. I noticed the battery cables were frayed so i repaired them but it was a no go. None of the 12 volt lights/outlets have worked since. The system control reports a full battery and oddly enough, the fan on the range still works. I tested all lines at the fuse box and everything checked out. There is one orange line that runs off of a terminal on the fuse box but i've yet to identify it.

Anyone have any ideas as to what could be causing this?

[4RXLA]

I'm no 12v expert but I'm wondering if the univolt is shot? or the fuses blown?

[Aage]

Originally Posted by dougsale

I'm no 12v expert but I'm wondering if the univolt is shot? or the fuses blown?

I agree. Both are likely, and if you have a Univolt converter, change it ASAP plus replace the 12V fuse panel.

Most better modern 120-12V converters have three stages of charging that protect your battery. The old fuse panel may have changed state and be providing more resistance than is healthy.

It's something that, if you don't do it now, you will not be completely happy until you do...

[GreyMattr]

Thanks Dougsale and Aage; I'll pull each of the fuses and double check them. Any recommendations as to a "preferred" converter to replace the univolt with?

[TG Twinkie]

I would check all of the ground/common connections. While the Univolt may be a problem. If the battery has a good charge you would not need the Univolt.
Also check the connections (tighten all the screws) at the fuse panel including the fuses themselves. If the fuse holders are lose or corroded it could be the reason for your intermittent problems.
Check for wires that look like they have been hot, look for discolored insulation near the connections.
I would certainly consider upgrading to a better converter. I recently upgraded to a Progressive Dynamics Intellipower 45 amp converter and am real happy with it. You can find them on eBay for less than $125.00.
If you have a portable battery charger, disconnect the shore power cable and connect the battery charger to the battery and see if things work. These monitor panels are known to be unreliable.

[GreyMattr]

I'll do another go through on the fuse box and dig through my manual for the wiring diagram. I'm planning on taking a lot of pictures from now on so I'll have something to put on here to help me explain. (i.e. the orange wire in OP).

@TG Twinkie - Thanks for the recommendation on the converter. Also, is the amperage on the converter a matter of preference, performance, or OEM specs?

[TG Twinkie]

My trailer is a 26' and 45 amps is more than enough. It originally had a 30 amp Univolt.

[Bfrank]

Check your fuse panel mine had resistance between the rivets of the metal clip on each end of the barrel fuse. I drilled out the rivets and cleaned up everything replaced rivets with small machine screws and lock washer and a nut no more 12v problem. The fuse clips had corroded between the strip they were riveted to and the clip check both sides and you will have to remove the fuse panel to check and repair. From my experience most of my 12v problems have been due to bad grounds or corrosion like described above. Just my 2 cents worth.

[GreyMattr]

So, I finally got to tear into the electrical issue and I've made some headway. Surprisingly enough, the fuses all checked out. While testing various circuits and fuses, the lights began to work intermittently. After an hour of frustration, I took a break and picked up on removing all of the furniture. I happen to notice a flicker at the fuse panel. Upon closer inspection, i noticed a small fire trying to happen at one of the connectors. I wiggled the fuse and I was pretty much able to mimic the bad behavior. I will be replacing the fuse panel and the converter for good measure.Thank you to everyone who posted advice, it's greatly appreciated.