Converter Bad? Please HELP!

On our 5th wheel the black is positive and the white ground. Look at the cables you are attaching to the battery. One of them should be attached to the frame fairly close to the battery. That one is ground. After this you will be sure of the battery end.

Since your problem started from an already working system, I would leave the battery disconnected and check the output from the converter. It is possible the converter went bad and you have a short within that is blowing the fuses.

Thanks for the suggestions - I will work on testing the current converter. That's the thing - I did nothing to the batteries before taking the last trip and the fuse blew, while on shore power, in the middle of the night. I knew these were called "reverse polarity" fuses, which is why I checked the new battery connections several times. I'll check 2 more times.....

Thanks again and will report back.

That Schumacher converter is a single stage charger (Winnie went cheap)

The 30A fuses are 'reverse polarity' fuses and should blow when/if battery is connected backwards.

Follow battery negative cable to frame .....ground

With battery cable disconnected....converter show not blow those 30A fuses and DC output should be 13.2V DC minimum when on shore power.

HERE is some info on upgrading to multi-stage charger and better yet replacement.

Typically those are called reverse polarity fuses. Did you do any battery work before the trip?

I would remove the battery cables, insert fuses and plug in to check the converter. Then check polarity of the cables with a meter or test light. If the fuses open with no battery then you have a short to be found and repaired.

Disconnect the wires from your battery and then measure at the converter to see the converter output. It should read about 14 volts.

If it does, connect the positive side to the battery and use your jumper cables to connect to the negative terminal on the battery, and to the negative bus on the converter. If the fuse does not blow now, it is the negative wire loose somewhere.

Try the same with the positive wire to the positive bus. If connecting with the jumper keeps the fuse alive, it is the positive feed to the battery.

Usually, when replacing converters, the connections to these wires are all made tight again.. so check carefully to see if yours are loose before throwing out the converter.