Monitor Circuit Blows Fuses

[jeffk14]

I have a 2008 Palomino Puma travel trailer. The 15A fuse for the monitor circuit blows immediately when inserted. I have 12v to the hot side of the fuse and the load side of the fuse is shorted to ground. I am very familiar with electrical troubleshooting (35-year aircraft mechanic) but without a wiring diagram, I don't know what all is on this particular circuit.

I also have a couple of outside lights not working, the ignitor for the gas water heater will not fire, the water pump will not come on and the light and fan in the range hood is inop. I'm thinking that there is a possibility that all these items might be on the monitor circuit. The monitor panel is completely dead. No lights at all, including the water pump and water heater switch lights. The electric water heater works though.

I've already eliminated the water pump and the monitor panel itself from being the source of the short. By the way, I just bought this camper last week. Thanks!

[MrWizard]

glad you found it
thanks for the update

[enblethen]

Thanks for the update!

[jeffk14]

Well, I found it! After much trial and error with a multimeter, I found where, for some reason, a previous owner had cut the wire in two, stripped the ends back and stuffed them back into the wall where the TV cable outlet is located. The wires, of course, then shorted out against the metal skin of the trailer. I repaired the connections and now all of the components that were inoperative in my original post work! Even all the tank level sensors seem to be working normally.

[enblethen]

If the lamps are corroded in the sockets and switch is on, that cause issue.

[jeffk14]

enblethen wrote:
Have you disconnected the wiring going to the exterior lights that don't work?

That's on my list of things to check. I won't be able to get back down to where the trailer is to work on it until Thursday.

[enblethen]

Have you disconnected the wiring going to the exterior lights that don't work?

[jeffk14]

MrWizard wrote:
IIRC the guages all work simialr to automotive
in that the monitor panel is hot and the guages all goto ground

if its NOT the water pump, or pump controller, or water heater switch

then one of the sensors as shorted to ground OR the wire to the sensor has shorted out
fw, black tank, gray tank

Now that's interesting. The monitor panel is completely dead. Nada. The shorted load-side wire at the monitor fuse is white/brown. I pulled the panel and disconnected the only white/brown wire that was back there. Still shorted to ground at fuse. That tells me that the short is somewhere "upstream" of the monitor panel and the sensors. Either a rubbed through wire upstream, or a faulty/shorted component that shares that circuit.

[jeffk14]

Duplicate post. Sorry. :S

[jeffk14]

enblethen wrote:
Does your rig have multiple switches to turn water pump on? If the answer is yes, look around near the 12 volt DC panel for a water pump controller. Mine is hidden next to drawers in that area.
The water pump controller, or some, switches the ground. testing the pump circuit would require disconnection both wires.
Water Pump controller

Only one water pump switch, on the monitor panel. Disconnected wiring completely from water pump. Fused wire going to pump, fuse was good. No help. Still short to ground on load side of monitor fuse with pump disconnected.

[MrWizard]

IIRC the guages all work simialr to automotive
in that the monitor panel is hot and the guages all goto ground

if its NOT the water pump, or pump controller, or water heater switch

then one of the sensors as shorted to ground OR the wire to the sensor has shorted out
fw, black tank, gray tank

[enblethen]

Does your rig have multiple switches to turn water pump on? If the answer is yes, look around near the 12 volt DC panel for a water pump controller. Mine is hidden next to drawers in that area.
The water pump controller, or some, switches the ground. testing the pump circuit would require disconnection both wires.
Water Pump controller

[road-runner]

It wouldn't be unusual for most or all of the items you mentioned as inop to be on the same circuit. My instinct would be to start removing all the items from their circuit one-by-one, and hope the fault is in one of the devices and not in the wiring buried in the wall or ceiling. If that turns out to be the case it wouldn't be the first time something like a screw or staple was driven into the wires.