LPG always empty on Monitor Panel

Hummelr · 02-27-2021, 10:01 PM

I very recently bought a used 2021 Outlaw 29S.

I just noticed that I only get 1 light on the LPG reading on the monitor panel even though the tank visible sight gauge is 3/4 full. All other measurement stuff on the panel appears to work. I jiggled and felt the black sensor on the sight gauge and it is warm but did not change the readings.

The tank is a Armebe.

Any ideas on what is wrong?

OldWEB · 02-27-2021, 10:41 PM

I have never noticed any heat on the sender unit. There are videos on how to check some things, here is what the late RV Doctor had said.

Bob Denman · 02-27-2021, 11:00 PM

... And welcome to the forum!

Hummelr · 02-27-2021, 11:24 PM

Thanks. I will check out YouTube.

The sending unit is definitely warm.

Bob Denman · 02-27-2021, 11:34 PM

I'd unplug it until you've had the chance,to research this further...

Hummelr · 02-28-2021, 12:16 AM

Will do. Thanks

javelin · 02-28-2021, 06:02 PM

Attaching a troubleshoot listing from Ventline who manufactures some of the Monitor Panels in RV's. They suggest a reading of empty all the time (even when the LP tank is known to contain fuel) may be as a result of a short to ground on the sensor wire from the LP tank. If you disconnected the LP sensor wire from the Monitor Panel end you should now read a full tank (if similar to Ventline product). If that monitor panel reading is working OK, then likely the trouble is either a grounded sensor wire (maybe chafing through wire insulation has shorted the wire to ground), or perhaps the LP tank sensor has failed to ground. You could then try to isolate the LP tank end (if that is even possible at your sensor) and determine if the sensor wire itself is grounded to chassis with a multimeter (ohmmeter). Never use the ohmmeter setting on live circuits though.

Hummelr · 04-09-2021, 03:51 PM

Thanks for all the responses.

We finally got home to my ohm meter.

I am getting about 68 ohms on the exterior sending unit.

I am also getting about 68 ohms all the way to the interior control panel plug that connects to the interior panel itself.

I have sent an email to Thor asking them if they will replace the little green circuit board.

I will keep you updated.

OldWEB · 04-09-2021, 05:06 PM

Did you try the two checks in the post from javelin? Where you first disconnect, then 'short' the two wires? Results?

Hummelr · 05-13-2021, 04:43 PM

I tried the test that javelin suggested. I received the new board from Thor today. No luck. I tried to trace the wires but get lost under the RV. What I did discover is that if I connect either black wire from the gague attached to the tank to just 1 wire (either white or orange) i do get a reading of 2/3 which is about what the tank is reading. If I connect both black wires to either the orange or white I also get 2/3 reading. If I connect all 4 wires together, I read empty again

Hummelr · 05-13-2021, 05:09 PM

Well, ignore what I just posted. After I put everything back together again, I noticed a 5 amp fuse was blown. This is to the propane leak detector. It has blown several times. I noticed that when this fuse us blown, my slide will not retract. I have read another thread that talks about this. There is no solution on that thread. Anyway, somehow that 5 amp fuse also effects my issue.

Hummelr · 05-13-2021, 05:19 PM

When that 5 amp fuse is also blown, my winegard internet shuts down and that is entirely on a different fuse

Bob Denman · 05-13-2021, 05:22 PM

Quote:

Originally Posted by Hummelr

Well, ignore what I just posted. After I put everything back together again, I noticed a 5 amp fuse was blown. This is to the propane leak detector. It has blown several times. I noticed that when this fuse us blown, my slide will not retract. I have read another thread that talks about this. There is no solution on that thread. Anyway, somehow that 5 amp fuse also effects my issue.

I'm glad to see you solved that mystery.

John & Diane · 05-13-2021, 10:35 PM

Just recently I had to replace our Propane/CO detector because it aged out. When I went to change it I couldn't get to the connection point where Thor attached the detectors wire to their harness. My dilemma was that there were two red positive wires and one black ground wire on both the new and old detectors, which was which, or did it matter?? I checked the wiring diagram I have for our MH but couldn't find the CO detector on it so I called Thor for an updated drawing. The tech at Thor couldn't find the CO detector on their drawings either so they passed my inquiry up the chain for an answer. The next day I received a call and was told they weren't sure why they couldn't find a print with a co detector shown,but h since I was replacing the original one with an identical model I should replace one wire at a time based on the wires location on the detectors, which worked.

Based on the instructions that came with the new unit you can have two fused power sources for it or connect both wire together and connect that to one fused circuit. Based on the these post I'm beginning to wonder if the CO detector circuit powers other THINGS. Also my CO circuit has a 15 amp fuse and it came that way from the factory. We are the original owners and have never had issues with that circuit or reason to change the fuse. I did just pull that CO fuse and checked the LP level and it continued to read full.

Hummelr · 05-15-2021, 08:36 PM

Thanks for the info. I do not believe that the sending unit for the LP amount should even be fused. I believe it works on resistance. I sent an email to Thor to the gentleman who sent me the new panel. I hope he has a solution. I also pulled my detector and it has only 1 red and 1 black wire. The red wire connects to an orange wire and it is an orange wire that is attached to the fuse. Who knows what happens behind the walls.

javelin · 05-17-2021, 12:07 AM

Quote:

Originally Posted by Hummelr

I tried the test that javelin suggested. I received the new board from Thor today. No luck. I tried to trace the wires but get lost under the RV. What I did discover is that if I connect either black wire from the gague attached to the tank to just 1 wire (either white or orange) i do get a reading of 2/3 which is about what the tank is reading. If I connect both black wires to either the orange or white I also get 2/3 reading. If I connect all 4 wires together, I read empty again

Well getting a resistance measurement of 68 ohms is encouraging assuming this is your resistance reading across the two black wires coming from the propane dial sensor mounted on the tank. Since there are two wires coming from the propane tank dial sensor back to the level sense control panel it suggests that the control panel likely provides a ground and some positive voltage via the “green circuit board” electronics for the propane tank dial to function correctly via changing resistance. If there was one wire coming from the propane tank dial sensor then it would be likely that the dial would be grounded at the propane tank and the single wire would be the resistance wire sense signal going back to the level control panel.

Maybe the 5 amp fuse that blows powers the propane gas detector as well as the green level sense control board (and maybe some other low current “control” items as you describe not working when this fuse blows). Maybe when you short all four wires together you are blowing the 5 amp fuse? Maybe shorting the orange and white together is actually causing the fuse to blow? You don't mention where the orange and white are coming from unless I missed it.

Replace your 5 amp fuse with a good 5 amp fuse and using your voltmeter setting, measure the voltage on both the separate orange and white wires with respect to a “known good” ground. What voltages do you measure? Do not accidentally touch the orange and white wires together or to coach ground. Also keep the two black propane dial sense wires from touching either orange or white for this test. Now remove the “good” 5 amp fuse and re-measure your two voltages (on the separate orange and white wires) referenced again to a known good ground. Has anything changed?

Part of this problem is trying to determine what is being tested and if the black wires are being connected to the green level sensor board correctly.

Hummelr · 05-17-2021, 05:57 PM

Interesting:

Outside at the LP tank I get the following:

With the 5 amp fuse in, I get 13.1 volts on the Orange wire
With the 5 amp fuse in, I get 0.0 volts on the white wire

With the 5 amp fuse out, I get 0.8 volts on the Orange wire
With the 5 amp fuse out, I get 0.0 volts on the white wire

Inside at the panel I get the same readings except when the fuse is out, I get 0.9 volts from the Orange wire and White wire when I use the multi-meter on them at the same time.

With the fuse out, the correct reading shows up on the interior panel.

The Orange and White wires connect to the 2 black wires and should be going to the little square board on the interior panel.

On my initial post, I noted that the black part of the sending unit was warm to the touch. It still is warm if it is connected to the orange and white wires.

I have not been keeping the black wires connected to the orange and white wires and the sending unit is no longer warm.

Rick

javelin · 05-17-2021, 07:08 PM

So from your meter readings it is “likely” that shorting orange to white in one of your previous tests is very likely blowing the 5 amp fuse and killing the propane detector and the other loads/functions you mentioned that are strangely connected and powered from that same 5 amp fuse. When your fuse is good and plugged in and the 68 ohm resistance sensor black wires are each connected to white and orange wires (assuming you have not used any propane from the tank to change that resistance value) you are drawing approx 0.2 amps through the 68 ohms......roughly 2.6 watts.....which is likely why the variable resistance sensor at the propane tank gets warm to the touch. That does not sound normal to me.

You say when the 5 amp fuse is out and each propane tank sensor black wire is connected to each of the orange and white wires (one black to orange; the other black to white) you get correct readings on your inside coach level sense panel? Sounds like the 5 amp fuse wiring is somehow connected accidentally to the orange wire directly (like a short circuit or it is mis-wired somehow)? Might have to get specific wiring details from Thor on that 5 amp fuse load and what fuse is supposed to be powering the level panel inside the coach. Maybe the level panel is powered correctly when the 5 amp fuse is out through some other "assigned fuse" for the level panel.....and works fine when the 5 amp fuse is out. Sounds like a wiring fault to me.

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