Using batteries alone

If the converter is causing problems, I would pull the fuse from the converter to the panel, or the wire if necessary. Then you should be able to charge the battery by any alternate means and use anything else in the camper. I forget exactly what it looked like on my 98 Bigfoot, but like my 2008 it is pretty simple.

Shorting a fuse back by the battery suggest perhaps another problem rather than the converter and that may take more time to track down.

That is what I am hoping. It is melting the fuse back by the batteries. He is going to do a check on the converter but we have pulled that fuse. I also think I am going to have to change the fuse holder in the battery area. It is pretty rusted.

Yes you can disconnect the converter and charge the battery direct with any portable charger as a temporary solution even if for a few weeks. If spending money get 5 to 10+ amps for that portable charger.

Get a real battery charger.....the trickle charger will only keep the battery fully charged if it's already charged and you don't run anything. A 25 amp charger would suffice for a really long time. Something like this:

https://www.amazon.com/Schumacher-SC1280-Charger-Automotive-Batteries/dp/B0797KK3N2/ref=sr_1_4?dchild=1&keywords=shoemaker+12+volt+battery+charger&qid=1591059920&sr=8-4

What fuse by the batteries?
The only 1 I can think about in this location would be inverter fuse, who is >=100 amp.
Converter has 2 fuses/breakers on its panel.
1 is AC breaker who is disconnecting 120V and the other, depends on the converter size is ca 40 amp fuse on 12V feed.
Usually flipping 120V breaker disconnect the converter, but if it is shorted inside, it should burn the 40 amp fuse.
Disconnecting both fuses will put converter out of business and allow use the camper with truck charging.
Now buying battery charger those days is tricky. You can't compare $30 charger to $200 converter.
Lot of bigger chargers have automatic desulfation mode, what brings havoc to RV use. Than cheap trickle chargers will go as high as 16V, what can boil the battery dry.
I am using 20 yo converters and when I don't like the 14.2 voltage they supply for long storage, they work fine otherwise.

I have 3 fuses back by the battery. The first one is a 30 amp and if you do anything it melts. The other two are 10's, they seem to be working. We still need to track down where the problem is. At this time I have just removed it. The mechanic believes it is the charging line to the battery from the converter but we haven't confirmed that. I am borrowing a trickle charger until we find a final solution. Without an electrical diagram it is hard to say what feeds what.

If the mechanic can't tell you where the wire is coming from - time to look for different mechanic.
Post some pictures and maybe member with similar set can make sense out of it?

rutzbeck wrote:
I have 3 fuses back by the battery. The first one is a 30 amp and if you do anything it melts.

The 30 amp must be feeding the panel. "If you do anything it melts" - like do what? If there is a short somewhere, just inserting the fuse will cause it to melt. Is that what happens, or do you have to operate something to blow the fuse?

Any good battery charger can be used temporarily, but it’s unlikely a trickle charger can keep up with your battery usage. On the other hand, you have to be careful using a regular charger because it can overcharge your batteries.

You could also consider adding solar which can charge a battery assuming there is sun. Finally, think about putting in LEDs or don’t use the lights. They draw batteries down like crazy.

Does the converter work?
IE, battery disconnected, camper plugged in to AC power, does all the 12V stuff work?
Problem is a bit perplexing not seeing it in person, but TC electrical systems are super basic. Likely a live short in the converter, or somewhere on that charging line (which is strange as not alot of opportunity for a wire in an old camper to ground out on a large piece of steel).