Power always on regardless of disconnect switch

[UT_Grandpa]

I turned off my disconnect switch and, as expected, lights, furnace, water pump, stereo, fridge, etc. DC power is off. However I have a digital voltmeter plugged into the power outlet/USB charger outlet on the panel to the side of the Murphy bed stays on all the time.

In tracing wires from the battery hot side of the disconnect switch I see a small gauge wire going to the brake break-away switch (normal) and a larger cable running through a 20 Amp fuse goes back into the junction box behind the tongue.

It looks like this outlet (and who knows what else) is hot all the time. Not a big deal unless the USB charger pulls idle current (I don't think it does but haven't measured it yet).

Is this what others are experiencing? This outlet is not on the fuse panel but wired directly to the hot side of the battery switch.

Thanks

[wmtire]

Are you talking about a 120 volt outlet that has a 12 volt DC USB port to it?

If so, then when you are connected to 120 volt AC power, it has built in circuitry to convert it to 12 volt DC for the USB ports. It doesn't need power from your battery.

These work the same in stick and brick houses.

https://iaeimagazine.org/magazine/20...-usb-chargers/

[5picker]

Not all 12v disconnect switches disconnect everything.

They often do not disconnect the CO detector and as you have found your USB outlets.

If you want to disconnect everything you need to put ALL feed wires on the disconnect side of the switch or remove one of the battery cables.

[TitanMike]

Originally Posted by 5picker

If you want to disconnect everything you need to put ALL feed wires on the disconnect side of the switch or remove one of the battery cables.

An easy cure to parasitic current draws HOWEVER, if a towable RV DO NOT TOW with switch off. If one does there will be no power to the breakaway switch. Might be best to leave that wire connected to the always hot side of the power switch.

[5picker]

Originally Posted by TitanMike

An easy cure to parasitic current draws HOWEVER, if a towable RV DO NOT TOW with switch off. If one does there will be no power to the breakaway switch. Might be best to leave that wire connected to the always hot side of the power switch.

Correct Mike.
A breakaway switch draws no power unless the pin is pulled so it isn't a parasitic draw anyway but certainly needed for emergency braking.

[TitanMike]

Originally Posted by 5picker

Correct Mike.
A breakaway switch draws no power unless the pin is pulled so it isn't a parasitic draw anyway but certainly needed for emergency braking.

Understood. Likewise for tongue jack, slide, and awning power connections.

Brought up brake wire because of it's importance.

[UT_Grandpa]

My CO detector, smoke detector go off with the disconnect switch. The two things that stay hot are the break-away switch and the "Charging Center". As mentioned before, the Charging Center is the cigarette lighter socket and two USB connections. The charging center has a 20 Amp fuse under the tongue, and with nothing plugged into the center the current draw is zero - no parasitic draw on my trailer with the disconnect switch off.

So I can charge with or without the disconnect switch closed.

[hikerjohn7]

Originally Posted by UT_Grandpa

I turned off my disconnect switch and, as expected, lights, furnace, water pump, stereo, fridge, etc. DC power is off. However I have a digital voltmeter plugged into the power outlet/USB charger outlet on the panel to the side of the Murphy bed stays on all the time.

In tracing wires from the battery hot side of the disconnect switch I see a small gauge wire going to the brake break-away switch (normal) and a larger cable running through a 20 Amp fuse goes back into the junction box behind the tongue.

It looks like this outlet (and who knows what else) is hot all the time. Not a big deal unless the USB charger pulls idle current (I don't think it does but haven't measured it yet).

Is this what others are experiencing? This outlet is not on the fuse panel but wired directly to the hot side of the battery switch.

Thanks

Yes, I don't know what appliances are using it but when I turn off my master power switch inside the coach and leave my rig stored for a while, it drains the batteries. So I installed a marine type main switch right in the negative line from the batteries. Now I can turn off all the power and my batteries don't drain even after prolonged storage

[papafly]

On my 2019 2507s, the yellow wire with the inline fuse that bypasses the disconnect switch goes directly to the solar connector on the passenger side of the trailer. The smaller (20 awg?) Which also bypasses the disconnect fuse is the feed for the trailer brake breakaway switch. I will check my USB center with and without the disconnect switch tomorrow. I believe my CO and propane monitors are switched by the disconnect switch.

[campers302]

Originally Posted by TitanMike

An easy cure to parasitic current draws HOWEVER, if a towable RV DO NOT TOW with switch off. If one does there will be no power to the breakaway switch. Might be best to leave that wire connected to the always hot side of the power switch.

Are you telling me that if I turn off my 12v switch on the front of the TT by the battery that if my TT comes loose from the hitch that the breaks will not engage?


Shouldn't that, if anything else on the TT, be a all the time hot connection.



Are you certain of this or have I just misunderstood?


Waiting for the answer.

[bikendan]

Originally Posted by campers302

Are you telling me that if I turn off my 12v switch on the front of the TT by the battery that if my TT comes loose from the hitch that the breaks will not engage?


Shouldn't that, if anything else on the TT, be a all the time hot connection.



Are you certain of this or have I just misunderstood?


Waiting for the answer.

The emergency breakaway switch should NOT be affected by the disconnect switch.
If it is, it's wired wrong.

[dward51]

Originally Posted by bikendan

The emergency breakaway switch should NOT be affected by the disconnect switch.
If it is, it's wired wrong.

X2!!!! The emergency breakaway should be "hot" all the time. Also I do not think they are fused either. Direct from battery to switch.

[papafly]

It is an always ON connection. On my trailer 2019 2507s, There are only two DC wires coming from the battery that bypass the disconnect switch (always hot). One is the yellow "breakaway" switch that activates the brakes if the trailer gets away and the second is also yellow and fused with a 20A inline fuse before it joins with a Red with White trace wire that goes directly to the ZAMP solar connector on the outside of the trailer (not in use on my trailer).
The USB Command center mounted on the passenger end of the nightstand is off when the main DC disconnect switch is opened.
The Carbon Monoxide/Propane Gas Monitor is ON when using Shore Power and ON when using DC Battery Power, but is OFF when both the AC Shore Power and the DC Power are off (Shore Power disconnected and Main disconnect switch open)
Who knows how any individual trailer is wired....it seems that it probably varies at least day to day depending on whos doing the wiring at the factory and how close it is to quitting time or what wire is easiest to grab or whether it's Monday or Friday or for that matter any day that ends in "y".
Good Luck

[campers302]

Originally Posted by papafly

It is an always ON connection. On my trailer 2019 2507s, There are only two DC wires coming from the battery that bypass the disconnect switch (always hot). One is the yellow "breakaway" switch that activates the brakes if the trailer gets away and the second is also yellow and fused with a 20A inline fuse before it joins with a Red with White trace wire that goes directly to the ZAMP solar connector on the outside of the trailer (not in use on my trailer).
The USB Command center mounted on the passenger end of the nightstand is off when the main DC disconnect switch is opened.
The Carbon Monoxide/Propane Gas Monitor is ON when using Shore Power and ON when using DC Battery Power, but is OFF when both the AC Shore Power and the DC Power are off (Shore Power disconnected and Main disconnect switch open)
Who knows how any individual trailer is wired....it seems that it probably varies at least day to day depending on whos doing the wiring at the factory and how close it is to quitting time or what wire is easiest to grab or whether it's Monday or Friday or for that matter any day that ends in "y".
Good Luck

Thanks to all that replied. I got real concerned on the post. Thanks again to all.