Gas and CO Detectors

[tropical36]

Just noticed that both of these units are dead and aren't receiving the required 12VDC. All fuses on my DC house panel are good and I can't believe that it would be coming from chassis power. I did find some paperwork from National that says it's fed from a 1.5amp fuse, located in the main panel. I assume this to mean the AC breaker box which does indeed have a DC panel and also a fuse, but it's 3amp and obviously for the EMS. I'm about out of ideas here so hopefully someone else can help that has possibly experienced this.
I have every unit pulled thats in between these detectors trying to see whats going on with the wire harness and am about ready to run a new circuit altogether if I don't find the problem soon.
I've tried everywhere else, so maybe someone here knows the answer.
Thanks in advance...

[Pigman]

The first thing I'd try is checking every single 12V fuse you can find with a good meter. Regardless of who builds the coach, I have found any number of mis-labeled cb's and circuit designations. Be sure you check in and around your battery compartment. Builders have a habit of wiring these directly to the coach or engine batteries. Beyond that, I don't know what tools you have access to, but putting a circuit tracer on your wires might be a way to see what's ultimately powering them. If these efforts are unsuccessful, a rewire would work. Just know what you're using to power them so you can be sure there is a fuse in the system somewhere.

Good luck,
John

[tropical36]

Quote:

Originally Posted by Pigman The first thing I'd try is checking every single 12V fuse you can find with a good meter. Regardless of who builds the coach, I have found any number of mis-labeled cb's and circuit designations. Be sure you check in and around your battery compartment. Builders have a habit of wiring these directly to the coach or engine batteries. Beyond that, I don't know what tools you have access to, but putting a circuit tracer on your wires might be a way to see what's ultimately powering them. If these efforts are unsuccessful, a rewire would work. Just know what you're using to power them so you can be sure there is a fuse in the system somewhere. Good luck, John

John.....
Thanks for your quick response.
I don't have a circuit tracer.
The only extra battery wire is from the solar cell which is connected to chassis power. I've checked every fuse I can find and feel that there's an inline hidden somewhere where it doesn't belong.
I've already decided on a rewire and have decided to take the pos side from the back of my tank level indicator panel (leaving the neg return as is) and installing an inline fuse in the compartment behind the LP detector. I'll mark both the detector and the manual for future reference.

[wa8yxm]

The first thing I'd do is check to insure you have 12 volts at the device not working. I mean no power there means "Problem up-line" and power there means "Replace me"

How to build a circuit tester/tracer for 12 volt

You will need

Some wire, about 3 feet, stranded, 20 or 22 ga is nice here

Two alligator clips

Some tape or heat shrink tubing, solder (And soldering gun) Optional

A license plate or other 2-lead single element light socket from an auto parts store.

Light bulb matching socket

On one lead of the socket install an alligator clip

To the other attach one end of the wire (Solder optional) Tape or heat shrink tube this joint to protect

On the other end of the wire,,, the other alligator clip

now.. Hook to a known good ground (either clip don't matter) and touch the remaing clip to the power lead for the device.. LIGHT = good power.. Dark = 12v problem

It's that easy

NOTE: Best ground is the device ground.. then if you get DARK try a different ground cause that can be the problem wire.

Also pick a different 12 volt (Working source) test point too.. a fuse block is nice if you have a long enough wire lead to reach it.. This confirms the ground is good

[tropical36]

Final update and solution....
Since the power source for these devices are nowhere to be found in the house and I wouldn't be interested in a fix if it turned out to be fed from the chassis, I did what I usually do in these cases and ran a new pos wire with a 2amp fuse. Left the neg return connected and we're now good to go. All the trouble shooting took up most of the time and nothing by comparison for the actual repair.
wa8yxm.....
Thanks for your efforts and suggestions, but it does sound like your build won't do anything more than my Digital Fluke.

[tropical36]

Maybe I'm still not done here yet. Now I wondering if these devices should be wired to chassis power since the coach batteries are the most likely to go dead with extended dry camping and I'm wondering just how low the voltage might drop before these devices become inoperative.
I'd appreciate any input on this.

[Scooter]

There are battery powered CO detectors, cheap to pretty expensive. Buy one.

Not sure about battery powered propane detectors.

[Pigman]

Quote:

Originally Posted by tropical36 Maybe I'm still not done here yet. Now I wondering if these devices should be wired to chassis power since the coach batteries are the most likely to go dead with extended dry camping and I'm wondering just how low the voltage might drop before these devices become inoperative. I'd appreciate any input on this.

On the CO detectors, when battery voltage drops the detector will start chirping. Lets you know when there's a problem. The coach builder will power these from any and all sources. Seems like each one is different.

John