Keep blowing my pump fuse

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Dmgoetz23

Member
Joined
Feb 4, 2016
Posts
9
Location
Monterey, CA
Hello,
In need of some help. I have blown the #7 blade fuse that is labeled Pump. This has made my monitor board, pump switches, water heater switch all stop working. I'm at a loss to what could be causing it. I've disconnected the pump and heater and still keep blowing the fuse.

What else am I missing?

Thank you


Edit by staff - changed message icon to topic solved
 
I would start by looking at the possibility that your hot wire is shorted to ground somewhere after the fuse but before the loads. (water pump. heater, monitor panel.  Probably a direct short to ground.

Start at the point where you know that you have power.  In this case the fuse holder.  Follow the wiring from that fuse and look for a break in the insulation or a place where it goes thru an opening that might be metal.  That would be the most likely spot for a short.

Another possibility if you cannot see an obvious short is that some times they use staples to secure wires to the wall.  Make sure a staple has not shorted a pair of wires.  This is probably not the cause but think of all the possibilities as you troubleshoot the wiring.
 
The fuse is doing its job protecting the wiring from overheating.

If you cannot find the short, there are a few different approaches you can use to identify the point of the problem.

You could divide the run of wiring in half if it is a single wire.  From the description it is probably one of several that go to different loads.

If it is just one wire or even if you have to do this several times on different runs or branches from that fuse, then this is what you can do.

By disconnecting the wire or wires at different lengths of the run you can isolate the short to an actual spot.  As long as you still have power at that point in the wire, then you have not reached the short yet.  The short will be between the spot where you have power and where you lose it.  This method is called signal tracing.

The other method is to run an alternate power wire to the load and then move back towards the fuse by tapping into the original run.  When you blow the fuse you will find the short between the last location and the new closer location.  This method is called signal injection.

Good Luck
 
If you use the signal injection method you need to disconnect the original wire as you move closer to the fuse otherwise you will probably backfeed to the short from the load end of the wire.
 
Is your water heater on electric? With hearing a hum from the circuit breaker I would think you have a direct short. Try turning off the electric at the water heater, maybe a bad element. Good luck and let us know when you find it.
 
shortie said:
Is your water heater on electric? With hearing a hum from the circuit breaker I would think you have a direct short. Try turning off the electric at the water heater, maybe a bad element. Good luck and let us know when you find it.
Click to expand...

The OP says that they're blowing blade type fuse so that tells me it's 12 Volt DC and not 110 Volt AC.
 
So, I have fixed my issue.  We traced the wire away from the fuse box, the wire splits out to many places.  We isolated the issue to about 12 feet of wiring that runs from one side of the coach over the ceiling, into the bathroom then to monitor board.  No idea what could have caused that piece of wire to ground itself.  So, we bypassed that section of wire and we are good to go.
 
I have the same issue. So did u just start pulling roof panels apart ??  Ugggghhhhhh. Seems like a mess. So it was above your bed where the issue was ??  Thanks
 
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