No battery power, blown 30 amp fuse

[bklarue]

Jayco X17Z

After having the battery on a trickle charger all winter I went to hook it up. No power. After some investigation I realized that the 30 amp fuse on the converter was blown, so replaced it. The second (and third) blew as soon as it touched the contacts.
I checked the inline fuse and it is fine. Positive and negative are correct. Ground wire to frame seems fine. I've visually inspected the positive wire from I can see and don't see any problems. I put in a new battery and had the same problem. I tried connecting the battery with a new fuse in place per the manufacturer recommendations.

What am I missing?

[Sundancer330]

For it to blow so quick it sounds like the pos and neg are backwards.

[bklarue]

Originally Posted by Sundancer330

For it to blow so quick it sounds like the pos and neg are backwards.

Just to clarify. The positive wire has the inline fuse, and the white wire is negative?

[JFlightRisk]

That's right. For some reason manufacturers use the same wire colors as a house breaker panel. With all the wires connected correctly on the battery, it may have a dead short somewhere. Not fun to find. With all fuses pulled for anything that is normally drawing current,(radio, co/propane detector, etc.) and the pos cable disconnected, connect a 12 volt test light in line between the pos battery terminal, and the pos cable end. If the test light glows, there's a current draw. Pull the remaining fuses one at a time to see if the test light goes out. When it does, that's the circuit that has a short. If no luck there, check out the circuits that normally are powered all the time. Those get more difficult. It really helps to have a helper at the battery, so you're not running in and out all the time. Just be sure everything is off, or fuse pulled to what you can't turn off, or you'll just be chasing your tail. Good luck.

[hoppers4]

Basically what FlightRisk said.

Start by pulling all of the 12VDC fuses leaving the converter. If the 30A fuse holds, insert fuses one at a time until you find the guilty circuit. If the 30A fuse still blows, could be a converter gone bad.

[RoyBraddy]

I alway double check by finding the word NEG or the symbol "-" stamped on tha battery case and make sure this is the terminal going to FRAME GROUND...

In the RV WORLD the colors are BLACK for HOT (+ 12VDXC )and WHITE for GROUND -12VDC.

The Automotive world has the colors RED for HOT (+12VDC) and BLACK for GROUND (-12VDC)

As you can see the BLACK CABLE is in both the HOT wired terminal or NEG Wired terminal depending on which world you live in haha...

Another clue as listed above the IN-LINE FUSES and CIrcuit Breakers etc will most likely be in the POSITIVE side of the terminals...

When you get it all figured out it would be wise to use some RED FINGERNAIL POLISH and mark all of the POSITIVE wired Terminals cable ends... Other folks like to take a CELL PHONE photo of the wiring to show them where the cable go. We all have our cell phone on us most of the time...

Also if the battery has had its fluids boiled out due to over charging with 13.6VDC coming from the converter/charger it may now have a shorted cell in it which will look like a direct short to the converter/charger as soon as it is connected...

You should have REVERSE POLARITY FUSES somewhere in the 12VDC Distribution Panel and an IN-LINE FUSE in the POSITIVE battery cable wiring close to the battery terminal that should be rated higher than the DC AMPS OUTPUT rating of your converter/charger unit.

Roy Ken