LPG/Propane detector wiring - 2018 Bambi 20 FC

[WizardOfAZ]

I have no power to the Atwood propane leak detector in my 2018 Bambi 20FB Flying Cloud. Not only no lights on the device, but I've tested the voltage at the wires. The meter shows 2 or 3 volts, not the 12+ that should be there. This is true irrespective of the position of the use/store switch. There is no evident damage to the wire pair between the device and the cable harness. I'm curious why it even goes into the harness, since the detector is only a few inches from the electrical panel, where it could have been wired directly.

Some background: The detector failed a while after, and probably due to, the refrigerator cabinet just above it coming apart on rough roads and dropping the fridge out the front. Broke the wood panel at the bottom of the fridge cabinet, in which is mounted the electrical distribution panel (AC and DC), and the propane detector. That's a whole 'nuther story, but I won't get into it here. In summary, nothing else electrical appears to be damaged from that incident, and even the propane detector was still working when I first began the project of putting things back together.

I've verified all the fuses are still good by measuring 12V at the output side of every fuse.

So to fix this, I'd like to know if anyone knows, how exactly is the LPG detector wired? I've read elsewhere that sometimes it's on the always-on side of the USE/STORE switch, sometimes on the switched side. Anybody know specifically how the detector is wired in this model, or better yet, a wiring diagram for this model? I have failed to find one that includes this detail. Any other relevant ideas also welcomed.

Thanks for whatever help can be offered.
Bill

[rmkrum]

My 2007 International CCD has a home run to the 12 volt connection on the input side of the use/store relay and a fuse. In my case it’s under the front bed. The fuse is NOT in the 12 volt fuse panel above the convertor. It’s totally separate and way up front far away from the propane detector.

There are usually a couple fuses in that area for the use/store relay, plus another for the propane detector. Mine are all blade fuses, IIRC.

[WizardOfAZ]

That’s a good hint rmkrum, thanks. I’ll look for fuses under the bed. In general, if there are fuses not in the panel it will be good to learn where they are and what they serve. Thanks.

[DillPickles]

In mine, the LPG/Propane detector is wired directly to the battery positive bus bar bypassing the USE switch completely. It is always on. The fuse is inline, not in a panel.

[rmkrum]

Originally Posted by WizardOfAZ

That’s a good hint rmkrum, thanks. I’ll look for fuses under the bed. In general, if there are fuses not in the panel it will be good to learn where they are and what they serve. Thanks.

When you trace them out, use your laminated tape label machine to attach the pertinent data about the circuit and fuse directly to the wire. Less pain later...

[Runamuk13]

My 2018 Bambi 16RB has the propane detector wired to the always-on side of the USE/STORE switch.

A loose connector or any kind of rust/corrosion can cause a reading of 2 to 3 volts.

[WizardOfAZ]

Some news on this topic: I sent a request to Airstream and I was impressed that they sent me the complete wiring diagram for this year and model. It’s not perfect but pretty close. It led me to the location of this fuse which is under the bed in a large plastic box with a big label 12 V distribution panel. The good news ends there. It is really hard to access this box. I can do it by crawling into the storage space under the bed and reaching over the wall that divides the storage from the equipment area. I can also access it through an access hole in the bed platform. But the access hole is small and very hard to get two hands in there to work and also see what you’re doing at the same time. I could take the whole bed apart But haven’t yet decided to do that.There are a three fuses in this box none of them obviously agreeing with what I see in the schematic and also none of them are blown. However there is a puzzle I haven’t yet figured out. On the connector block where these three fuses are is also a black mystery gadget that I’m trying to figure out what is it, and maybe, just maybe, it’s related to this problem. This black thing has an RJ 45 Jack on it. And there is also an unplugged RJ 45 cable dangling in the box. So probably I should just plug it back in. I’ve attached a picture though it’s pretty hard to take a picture in the space and so it may be hard to see the RJ 45 Jack. But it’s there on the black gadget that straddles the gray connector block. Anybody want to venture a guess (or maybe actual knowledge &#128556 what this thing is?

[WizardOfAZ]

Ok from some more searching of parts that can attach to that DIN rail, it’s pretty clear the black thing is a fuse holder. And from the docs AS sent, also pretty clear that it’s the LPG detector fuse. So maybe I’m almost done. Have to get back under the mattress to see, and right now it’s full of blankets, pillows, and people. But soon.

Still have not found specs on exactly this part and why it would have an RJ45 jack, and whether the dangling RJ45 cable should be plugged into it. I’m guessing it’s for remotely signaling the blown fuse indicator, but that’s just a guess.