Components not fused at 12v panel

[KYAvion]

I haven’t messed with my 12v distribution panel until today, and I discovered that many of the 12v components do not go through the 12v panel. So far, I’ve discovered that the following do not go through the panel:

Fridge - forget to check, but probably a fuse behind fridge

Water pump - fused at the pump

Direct Spark Ignition Water heater - fused near switch
behind Avion control panel

Tongue jack - fused in battery box

While I knew there were fuses for each item above, I guess I was surprised to see that each of them don’t also go through the 12v distribution panel.

[RISK]

That is an interesting discovery. Makes me wonder about my furnace which just decided to stop working. No fan, nothing. When I was flirting with swapping out my converter I checked all the fuses, good. Did the mud dawber check. So I was thinking ground, but I can’t seem to locate that either. Now I’m wondering if there is a fuse issue somewhere?

[KYAvion]

The furnace, range hood, and vent fans are all things I still need to check to see whether they go through the 12v panel. I assume they do, but I won’t know for sure until I run them and pop out the fuses one at a time.

Did you check to see if you have 12v AT the furnace via the wire connections?

[KYAvion]

Don’t forget your thermostat too. First I’d set your thermostat to ON with the temp way up and then check for 12v at the furnace. If nothing, then pop the thermostat off and connect the wires without the thermostat in place. Recheck for 12v at the furnace. If you’ve got 12v at the furnace, then you know the problem is the thermostat. Plus, if the furnace is fine and the wiring good, then it should start running with the thermostat bypassed.

[silverloaf]

My wiring schematic shows the water pump and heater sharing a common in-line 20A fuse behind the monitor panel. The fuse gets its power from the load side of the ammeter.

I’m not sure about the fridge. I found it plugged into a wall plug. No fuse was observed. Is it possible I have a 3-way fridge?

[KYAvion]

The plug you’re seeing is just the 110v plug. Three-way fridge runs on propane, 110v, or 12v. Two-way fridge runs on 110v or propane. However, I believe the display for both runs on 12v.

[RISK]

I haven’t tried bypassing the thermostat but I do get 12v at the furnace and the thermostat.
It happened after I ran out of propane with the furnace on. I refilled both bottles and have used the water heater and stove quite a bit. If it’s not the ground I’m suspecting a stuck sailswitch or something with the control board.

Sorry to veer from your original topic...

Ian

[KYAvion]

Gotcha. Don’t you hate it when coincidences like that happen. In the early fall I pulled my furnace for cleaning because some wasps had made a nest inside the squirrel cage. You could hear it clunking around when the blower initially turned on, as well as during shutdown. Anyway, I cleaned it out and reinstalled the furnace, and nothing happened. The blower didn’t kick on at all. I removed it expecting something to be interfering with the sail switch, but it moved just fine. I reinstalled the furnace and it worked. I’m not sure exactly what it was, but I suspect something was preventing the sail switch from returning to its original starting position, thereby preventing the initial electrical startup sequence from happening. Darn computer boards...

I originally thought the fan would initially run if the problem was the sail switch (since its purpose is to ensure the blower is working adequately), and then stop upon the sail switch not making contact. However, I had done some reading and learned that if the sail switch doesn’t return to its original position, then the furnace will not run at all. So it appears the switch can be problematic in either direction.

[RISK]

Yeah, it’s too convenient...
Except for getting to the sailswitch which is anything but.

[KYAvion]

I’m not sure about the Atwood, but the sail switch is pretty easy to get to on the Suburban once you pull the furnace out.