shorted out 12 volt system

[1856rmp]

I contacted chasis with wrench while tightening battery terminal and sparks flew. The 12 volt system is not working now as a result.Trying to figure out how to fix. 2005 Fleetwood providence 39L. Any suggestions as to figure out what to do

[OnaQuest]

Check all your battery connections again and make sure they are tight. Then go to your BCC (Battery Control Center) and reset the DC circuit breakers that you tripped.

[RLMiller]

The only way to fix a short circuit is to lengthen it. On the serious side, the entire thread is somewhat confused, vacillating between a “short” circuit and an “open” circuit. As stated by RJSfishin, there’s a big difference between the two. Based on your description of what happened, it looks like you have an “open” circuit, either due to a blown fuse, or a burned wire, caused by the high current short between the terminals, although a short across the battery usually will not blow a fuse, unless connected to shore power, in which case the fuse between the battery and 12 volt load will blow. A short across battery terminals can easily weld something, like the wrench, and is a dangerous act. A good practice when connecting a battery is to connect the ground terminal of the battery last so a wrench short to the chassis won’t make sparks and smoke.

[wrgrs50s]

It should not have caused any serious damage. Most likely you will find a fuse that is blown somewhere between the batteries and/or at the 12 volt converter.
If you can locate the battery bus bar there should be a resettable fuse there. On my 5th wheel the bus bar is near the battery mounted on the frame and has numerous wires coming off the bus bar to various places with small rubber boots surrounding them. One of those has a little square box with a very small button sticking out. This is a resettable fuse that can be reset by pushing in until it clicks.

Keep us updated as to what you find as a solution.

[1856rmp]

I was simply changing out the 4 house batteries. I THOUGHT I had negative terminal disconnected but is was touching terminal. Tightened positive next to block and touched chasis with wrench. Bummed out

[CA_Traveler]

Always remove the negative first and put it on last, safest way. For a MH remove the negative from both banks first just in case the isolator is engaged.

Check the negative to the chassis for any problems. Turn on some light switches so that there will be a load. Check for battery voltage with a voltmeter. Connect the voltmeter to a good chassis ground - NOT any cable. If you have 12 to the negative battery post the negative wire or connection is bad. Then with 12V on the positive post start tracing the wiring to the disconnects, fuses or CBs until you locate the problem.

A short on the battery might cause other problems, the charger might not like a short. Other devices might have storage capacity - think capacitance and might not do well with a short. Then a short of that size might cause very high voltage and amp transients which can cause damage.

[BTPO1]

To the OP if you tighten the Positive post first and then place the negative cable on the battery post and then tighten the Negative post this will not happen as there will be no current flow from negative to negative. JMO

[Chris_Bryant]

If the short was right to the positive battery terminal, I would look for an issue in the ground line. I just start at one end with a test light and go step by step to find where the power stops.

[RoyB]

It will put a short across the converter/charger output if it was powered up at the time (Connected to shore power)

Roy ken

[ScottG]

RJsfishin wrote:
I see no reason why anything would blow, except the battery. You did not over draw amperage thru anything, except the battery. Unless of course, the whole story is not been told 🙂

I hadn't thought of that but your right. Just a short across the battery puts no current through the RV.
What was happening before the battery was shorted?

[RJsfishin]

I could also add, your 12v system is not "shorted"
Your 12v system has a "disconnect"...or "open circuit" ?.big difference tween the 2

[RJsfishin]

I see no reason why anything would blow, except the battery. You did not over draw amperage thru anything, except the battery. Unless of course, the whole story is not been told 🙂

[ScottG]

When you say the 12V system, do you mean the chassis or the RV side? If you mean the chassis then you probably blew a fuseable link.

[1492]

Moved from Forum Technical Support

[RoyB]

Double post...