12 v short

[Don McKelvay]

My 1994 34 Limited has a short but I am having great difficulty. The circuit breaker #6 will not stay on and I have confirmed the breaker itself is OK. My manual does not specify what 12 v items are on that circuit. I do know the front ceiling light, light just inside the door on the right and the hot water heater switch do not work - everything else "seems" OK.
I have cut the wires to the the two lights and disconnected the wires that I could to the hot water heater and the breaker still blows.
Anyone have any ideas?

Oh, also I then installed a 110 v hot water rod but when it is plugged into the trailer 110 v the GFI circuit breaker blows and yet when I plug into a separate 110 v line to the house the hot water heater works and the 110 v circuit breaker is OK

[drboyd]

I'm smelling a rat in the water heater. Is it possible that the rod is hooked up in some excessively creative manner? Why don't you disconnect the 120 volt power to the water heater and see what's up?

-Don

[john hd]

don

have you disconnected the wires from the 12 volt breaker?

did you check them for shorts with a ohmmeter? you need to remove the load from the circuit and just check the wire itself.

one possibility for the heater is the switch itself. remove it from the bathroom wall and make sure the terminals are not touching the interior skin.

later model airstreams use high quality wire, but they are a little sloppy with the cutouts in the skin.

as for your waterheater, either it is defective or the polarity is reversed. either will blow a gfi circuitbreaker.

good luck!

john

[Don McKelvay]

Thanks for the ideas Don & John, unfortunately none of them worked. Well, not completely true as it seems there may be a short also in the 120 v Hot Rod which triggered the 120 v GFI. But this had nothing to do with the 12 v short as it was months after the short.- I only installed the hot rod a week ago.
I did disconnect the 12 v wires from the breaker but that only proved the breaker was working. My friend who is quite good with electricity came over (he also has a 1994 34 footer) and the only thing we can think of is there must a short between the inner & outer skin somewhere forward of the door. Even with all wires disconnected the breaker still blows so it must be in the wall. He used an ohm meter and the red (hot) wires were shorted to ground.
Still cannot determine what other 12v items are on that circuit #6. Anyone know?
I guess the only option I have is to take it to our dealer, but was really hoping to fix the problem myself.

[59toaster]

Ohhh man Hope and pray it's not in a wall. That would be an absolute nightmare.

Take a look around the coach for any thing new that's been added or recent repairs. If Airstream is still doing things like they did with our coach then most of the wiring is in the ceiling. Then it drops down into the wall. Look for things that have recently been service like over head fans, lighting, Fridge etc, A/C. It's possible as something was reinstalled a screw hit the wires. You might get luckly and back the screw out and it function. Then you will atleast know where the short is.

Is the Fridge working? Might also have the circuit for the controls on the fridge if your coach has a fridge that requires 12v.

[Don McKelvay]

Thanks for the idea, but unfortunately no cigar. The only repair was my dealer installed a Fantastic Vent in the front 3 or 4 months before the problem started. I have taken out all the screws in the various fans, lights; wiggled wires, etc. The only change was a once only time where the breaker worked for a few seconds and I heard the hot water heater switch click on when we wiggled the wires from the front ceiling light. Tried to get it to do it again for quite awhile with no success.

Just ran outside to check the fridge idea, but nope - the 12 v light inside worked fine.

And I really hope they do not have to tear out the walls or ceiling!
Thanks for the input.

[thenewkid64]

Don,

Does the "new" fan work?

If not it is 4 screws to pull the interior trim and try to fish the wires out. When they installed the fan did they screw it to the exterior skin or rivet it? If they used screws (not bad, just the way the instructions say to do it) one could have worked its way into the wire loom that runs right along side the vent opening. Might be worth a look wth a flashlight befor you tow it in.

I work in a technical field and if it was fine, then you did something and now it does not work (even if 4 months have passed) undo the last thing you did and 90% of the time the problem is resolved or identified. YMMV

[74Argosy24MH]

If your buddy has a tone tracer try that. Mine works even with the aluminum walls.

John

[Don McKelvay]

Hello helpers!

Bad News - Good News
My dealer could not locate the short which is in the ceiling/wall, but were able to do some rewiring so everything now works. It sure would have been nice to know where and why this evasive short was as this might have provided clues to otheres who might have the same problem later.
Only one small problem - the sconce light by the door must be powered by the light switch for the lights in the valances. This is a small price to pay rather than ripping out the ceilings/walls.
Oh well everything is OK.