In the event that you've been searching for an old atwood furnace wiring diagram, you're probably staring at the tangled mess of wires in your RV cabinet best now, wondering the reason why the heat won't kick on. It's a common stress for anybody owning the vintage rig or even an older recreational camper. These furnaces are usually legendary workhorses, but when they stop clicking or the lover runs without making heat, the very first thing you require is a map of where all these colored wires are supposed to proceed.
Let's be honest: obtaining a crisp, clean paper manual with regard to a furnace built twenty or thirty years ago isn't exactly easy. Usually, the initial sticker on the blower housing is peeled, passed, or covered in a layer associated with grime that makes it impossible in order to read. But don't worry, because most of these older Atwood models—like the 8500 or even 8900 series—follow quite a predictable logic when you understand the simple layout.
Exactly why the Wiring Diagram Matters So Very much
Whenever your furnace acts up, it's rarely a "total" failure. Usually, it's one specific element in the chain that isn't talking to the others. The old atwood furnace wiring diagram is your roadmap for testing those contacts. Without it, you're just guessing, plus guessing with a 12 volts system along with a propane source isn't specifically the best method to invest a Saturday afternoon.
The particular diagram tells you the sequence of events. Within a common Atwood setup, the power doesn't go to the burner and light the fire. There's the very specific "handshake" that happens between the thermostat, the time-delay relay, the particular motor, the travel switch, and the restriction switch. If any kind of of those components don't get the particular signal they anticipate, everything shuts down for safety. Pursuing the wires assists you find exactly where that handshake is definitely failing.
Comprehending the Standard Color Rules
While a person should always try in order to find the particular diagram for your own model number (usually found on a small metal plate inside the furnace door), Atwood was fairly consistent with their colors in the day. If you're looking at your furnace and seeing a rainbow associated with wires, here is usually what you're likely looking at.
Most of these older devices make use of a red wire for the main 12V good power originating from your RV's battery or even converter. Then you'll usually view a black cable serving as the terrain. The blue wires are nearly always your thermostat circuit. Once the thermostat clicks "on, " it completes the loop through those blue wires to tell the furnace it's time in order to get to work.
Then things get a little more specific. You might see yellow cables heading to the electric motor or the gas device, and sometimes the whitened wire involved in the ignition control. In case your wiring looks like someone do a DIY maintenance job in 1994, these colors may be faded or even swapped, which is definitely why having that will old atwood furnace wiring diagram will be so crucial to returning to the factory-standard setup.
The Sequence of Operation
One of the best ways to use a wiring diagram is to trace the path of electricity since the furnace attempts to start. It doesn't all occur at once. In the event that you know the particular order, you can use your multimeter to see where exactly the power stops flowing.
- The Call for High temperature: The particular thermostat closes the particular circuit. Power travels down the blue cable towards the furnace.
- The Period Delay: On many older models, the ability strikes a time-delay exchange first. This little part is responsible for beginning the fan plus letting it operate for a several seconds to purge any leftover fuel before seeking to lighting.
- The particular Sail Switch: Because the lover spins up, this pushes a little plastic material flap called a sail switch. This is a massive "fail point" within old units. When the fan isn't fast enough or the switch is usually dusty, the routine stays open.
- The High Limit Switch: The energy then passes through a safety change that monitors heat. If the furnace is too sizzling, this switch cuts the power.
- Ignition and Fuel: Lastly, the power reaches the control board, which usually sends an interest towards the electrode and opens the gasoline valve.
If you have your old atwood furnace wiring diagram handy, you can literally touch your multimeter probes to the particular terminals of each of these parts to be able. If you possess 12 volts going into the travel switch but zero coming out, you've found your culprit.
Common Problems with Vintage Wiring
Old RVs live a tough living. They bounce down highways, deal with extreme temperature swings, and sometimes become houses for mice. When you're taking a look at your own wiring, look out regarding more than just "where the cable goes. "
Corrosion will be the silent killer. Those old spade connectors can get a covering of oxidation that prevents electricity through flowing, even when the wire looks like it's plugged in tight. Sometimes, simply pulling a cable off, cleaning the particular terminal with a bit of sandpaper, and plugging it back in is enough to "fix" a dead furnace.
Another thing to look for is brittle insulation. Over decades, the warmth from the particular furnace could make the particular wire casings crack. If a bare wire touches the metal casing from the furnace, it'll whack a fuse immediately. If you find yourself replacing fuses every time the heat kicks on, you've definitely obtained a short a place in that wiring harness.
Obtaining the Diagram In the event that Yours Is Missing
When the sticker is gone and also you can't find the manual, don't anxiety. The web is a goldmine for archived documents. You are able to often discover a PDF of an old atwood furnace wiring diagram by searching intended for your particular model quantity on RV fanatic forums. Sites like iRV2 or various Facebook groups intended for vintage campers frequently have members that have scanned their original manuals.
When you perform find a diagram, it's a clever proceed to print this out or attract a simplified edition from it and strapping it to the inside of your own furnace access doorway. That way, the following time you're stuck in a frosty campsite at two AM, you won't have to go searching for it on your phone using a dying battery.
Safety First
I can't strain this enough: you're dealing with each electricity and gas. Before you begin poking about with wires, make sure your lp is turned away if you're performing anything that might produce a spark exactly where it shouldn't be. Also, keep in mind that actually though 12V DC won't usually provide you with a nasty shock like a wall outlet may, it can nevertheless cause a short that generates enough temperature to start a fireplace if you aren't careful.
In case you're looking with the wiring plus it looks completely melted or when someone has bypassed safety switches (like the sail switch or limit switch), cease what you're performing. These switches is there for a reason. Decoding them might get the warmth on for a night, but it also creates a massive fire risk. It's always better to change a $15 part than to risk the entire rig.
Final Thoughts on Old Atwood Units
These furnaces had been built to last, and usually, the mechanical parts—the blower engine and the burner—are still solid even after thirty years. The particular "brains" and the wiring are usually where the problems hide. Spending some time to study a good old atwood furnace wiring diagram provides you an enormous benefit. It turns the confusing box associated with mystery right into a logical system you can actually preserve yourself.
As soon as you get that wiring sorted as well as the sequence of operation working again, these old Atwoods put out a ton associated with heat. There's the certain satisfaction in hearing that "whoosh" of the burning illuminating, knowing a person fixed it due to the fact you spent the time in order to understand how the particular electricity was supposed to move. Grab your multimeter, discover that diagram, and obtain that camper comfortable again!