Electrical circuit dead

[mustang]

I am chasing a dead circuit.

I have a 1986 31 foot sovereign. Everything worked when stored. I am taking it out of storage because I sold it. Storage = parked next to my house winterized.

I am going through the systems, everything works. Exterior lights, brakes, Fridge, Stove, Waterpump, Hotwater tank and the interior lights except for....

The light over the counter between the stove and the sink, The light over head when standing at the sink, the exhaust fan over the stove, and .... The furnace....

Here is what I found, There is a big brown wire that normaly goes to the switch for the stove exhaust fan. It corroded and fell off, it was laying on metal, so I assume it shorted. I secure it, and all fuses, they are the 2 pole enclosed reset type, have power in and out. I loosed and retightened all the connections. I checked them with a trouble light. Power both sides. There has got to be another junction.

Does anyone know the schematic for this fuse panel? all I have is circuit and letters.....

I have no power to the thermostat which is in the rear bedroom.

Does low propane cause the blower not to run on the furnace? I know it will if there isn't enough, pressure not ignight the burner.....

I am grasping at straws now, so. any help will be appreciated.

[DKB_SATX]

If the furnace has power, the blower will run. That's the first phase of the cycle, before it even attempts to light.

Some of the big trailers had some 12v circuit breakers by the 80s, I think. If you had that kind of big short that didn't burn a fuse, it might have eventually worn out a "self resetting" breaker.

[mustang]

I snapped some pics.

The circuit breakers, so everyone knows which type.

The position with the hopes someone knows which is which.

The corroded wire over the stove.


And Its easier with pics....

Thanks, its gotta be a short, but all circuits have power on both sides of the fuse.

The brown wire hangin out (over the stove pic) is the wire that corroded off the fan switch. No power either.

[DKB_SATX]

My fault... I didn't note the extra detail you offered when you said you checked the fuses. "enclosed reset type" should have told me you were already looking at the circuit breakers.

I got nothin'.

[mustang]

Not a problem DKB.... I am trying to be specific, I know it helps especialy when people trying to help aren't present. Its kind of a handicap....

I am leaning toward a short, but cant find it, all circuits are powered, nothing tripped..... Frustrating. I also don't want to cause more issues or short out anything.


I ran a jumper to the stove fan, and to the lights, all work.

Everything has different colored wires going to it, so The red wire goes into the wall from the light and comes out brown at the ceiling light, and there is no wire at the box that isn't powered?

It would have been nice if Airstream used color coded wires throughout the circuit.....

[mustang]

Circuits check out at the box. The lights and fan turn slow and come on dim.

My thinkin is, all the power and ground lines come in for this circuit down by the furnace, and man they don't give much room to work on it, short of pullin the furnace.

[jbib]

The thermostat doesn't see power unless the furnace sees power. The fact that things spin slowly or light dimly suggest a bad ground. The circuits come down from the center ceiling panel. If the brown circuit has no voltage, that's the first issue. Good Luck, Jeff

[mustang]

The ceiling light is connected to a brown and a white wire. I used an ohm meter and the Brown wire at the fan, and at the light are the same. It doesn't make sense, cuz if I hit the brown with power, the light doesn't light up.

I need a shematic for this trailer.

[jbib]

The white is neutral. You said the light previously lit dimly but now powering the brown does nothing. Are you sure the light is still good? I think you need to check the furnace power supply. It does not seem to be getting power. If things are still dead at the furnace then I wonder about the brown connection at the fuse box which shows a wire nut. Is there power out of the wirenut?

[mustang]

All fixtures are good. No issues there. I need a schematic because up in the exhaust vent area there are a lot of wires, and also down by the furnace as well.

The light over the sink comes on but isn't bright, I don't want to short or burn anything up... it is so hard chasing wires. So the fuse panel is good, but this 1 circuit has issues.....

Using an OHM meter, both brown wires are the same, but when I hit it with power, it doesn't light the light. Everything cancels itself out it seems, that's why I wish I had a wire diagram

I did figure white was ground, and black power, but also have red and brown...Cant forget Blue. I assume they are power as well.

I am thinking, I have what is called a "Resistive connection"

Probably either in a wire down by the furnace compartment, or at a junction I cant find.

[TG Twinkie]

Do you have 12 volts between the white and brown wires at the light fixture?
Do you have 12 volts between the white and brown wires at the furnace?
Is the brown wire circuit the only one you are having problems with?
Do all of the ceiling fixtures work except the one you are working on?
Have you ID'd all of the circuits in the coach by removing one fuse at a time to see what goes off?
If you pull the fuse on the brown wire. What devices no longer work?
I am not aware that A$ runs any black wires on the interior of a coach. Most of what I have seen are pastel colors; pink, blue, brown, yellow, purple etc.
Black is the charge line.
Have you measured the voltage at the output of the 12volt breaker when the fan is running slow?
Try a fused jumper from the 12 volt buss to the brown wire. Bypassing the circuit breaker. It may be bad.

[mustang]

The brown wire seems to run between the range fan and the center light, and there is another wire feeding the sink light. I had the sink and over head light lit, but it was dim, when 1 was on it was brighter, and when one side of one was lit, it was brightest of all. At one point I heard the furnace fan come one, then all died instantly.

It seems I have voltage but no amperage. There is no power at the brown wire, and my ohm meter tells me they are either the same or connected. The brown is roughly 10 guage

I did try a fuse jumper, I unplugged the furnace ( I don't want to hurt the board) I made a jumper with an alligator clip, and jumped the circuits. Nuthin. SO I made an extension wire, and went up to the lights confirmed the worked, the hit the power wire with the positive jumper, and they came on, then when I disconnected the jumper they stayed on dim. then went out.

My issue with the fuse panel is, it seems it is prefabbed, meaning the wires coming off the fuse panel have a 3 inch wire with a yellow connector, so when AS installed it, the just crimped the wire to a circuit, speeding up the build process..... Very strange, since I am more an Old car person.

The lights are in great shape, prior to parking, and even earlier this year, everything worked great.

[garry]

Each individual fixture has it's own ground so I suspect you have a resistive connection some where between the fuse and the load or a bad fuse holder.

Sounds like you are saying there is a pigtail wire between each fuse and the downstream wire and that is where I would start.

Unfortunately a resistive connection is hard to find since it will usually read OK under a low load like a meter and still not work under a higher load.

[mustang]

Originally Posted by garry

Each individual fixture has it's own ground so I suspect you have a resistive connection some where between the fuse and the load or a bad fuse holder.

Sounds like you are saying there is a pigtail wire between each fuse and the downstream wire and that is where I would start.

Unfortunately a resistive connection is hard to find since it will usually read OK under a low load like a meter and still not work under a higher load.

Post 10

[jbib]

Airstream did not use wirenuts in the connections to the fuse panel. The brown wire is a hot circuit from the fuse panel. If you don't have 12v between Brown and ground that is a problem. You also asked earlier about blue wires. Usually the blue wires run to the thermostat. Red, Yellow, Pink, Purple, Brown, all interior circuits, all hot. Ask more questions? Jeff

[TG Twinkie]

If the pictures you have posted are the actual fuse panel.
You have a blue wire at that panel and it is not the thermostat.
Can you trace the wire which is connected to the wire nut?
Does it go to the upper left hand fuse? I notice there are 2 wires connected to that point.
Try moving the wires to the empty space on the right side of the fuse panel.
Also the brown wire hanging from the fan looks like it plugs in to something. Can you tell what?

[shelocta]

Mustang, I feel your pain. I've been chasing around a 12 V short on my 82 motorhome. From your descriptions I can't tell whether you have a open, gound, bad connection or a breaker that has malfunctioned but here are some general ideas. As goofy as it sounds I would go to the airstream site and look at the owner's manual for a newer trailer that best matchs your own. They will have a wiring diagram that is rather abbreviated but you can pick up a sense of how they're doing things and they do have some good troubleshooting tips. Sometimes I'm the last one on the form to figure something out but on the wiring it appears that they'll take a 12 V circuit and run it the entire length of the ceiling then anyplace they want current from that circuit they run a drop from the ceiling down to wherever make they're going a light switch, 12 V power outlet or a radio cluster whatever and the color is always consistent. For example in my motorhome if the wire is solid yellow I'm sure that it's a direct connection back to the fuse for the number two circuit. When airstream has a switch in a circuit the color of the wire that is on the switched side will be a different color, sometimes it makes sense like in my case it's yellow with a red stripe that feeds the overhead locker lights in other cases it doesn't make any sense. Although it may not solve all your problems I would concentrate my efforts on the least complex issue. I assume it's the lamp that is not bright when energized from the circuit breaker. With the lamp being fed by the circuit breaker try to figure out what the value ot the voltage is on the breaker side of the lamp. If it's near 12 V then you know you have a ground problem, if it's considerably less than 12 V then you need to start looking for a bad connection or your circuit breaker has a high resistance and also will be much warmer than the rest. If you would like more help PM me and we can set up something where we can talk back and forth over the phone. Good luck and happy hunting..... Bill
PS This may have to be settled in the court of Ohm's in law.

[jdalrymple]

The mention of dim lights and low fan speeds points to what you have said, voltage and no current.

Change the circuit breaker. The points in them can corrode or burn over and cause those issues.

Or I suppose, as a test, get a cheap in-line fuse holder and jumper across the suspect breaker and see if that corrects the problem.

Regards,

JD

[TG Twinkie]

I meant to say upper right, instead of upper left on the fuse panel.
Did you check the voltage at the fuse panel while you had the light and the furnace on?

[mustang]

Here is what I got....

Facing the computer screen on the left side of the fuse panel, there is a thin red and a thicker what appears to be pink wire. That is the one I am getting the Ohm reading on down by the furnace.

In the furnace compartment is where the wires disperse up to the lights over head ect.... SO I turned on all the light, disconnected the circuit right above it, swapping wires, the other circuit lit, but the light on the problem circuit did not so the fuse block should be OK since it didn't light the light over the sink. SO then I took a jumper, jumped from a known positive in the fuse panel, to the plug, which I unplugged from the furnace. The voltage fed back through, and lights came on,.

This tells me, I need to fish a new wire through for the one circuit....

When I got ohm readings it didn't zero out, it went from 1 to 15.16 so there must be resistance, but I would think, enough power would make its way through to light the light? Unless there is another junction.

Has anyone ever fished wires through an Airstream?

I would think with the rib cage design there has to be a rubber grommet in the ribs, and I don't know how tight it will be.