12V Disconnect Switch - What works, what doesn't

[Irlpguy]

I have been curious as to what load was on the batteries when the 12V disconnect switch was off and not connected to shore power.

Some on these forums have stated there are several items that are still connected and drawing current from the batteries even when switch is off. The following is for my 2012 – 3402RL and may or may not apply to any other models or in fact all 3402’s.

Smoke detector – 9V battery powered
Carbon Monoxide detector – 9V battery powered
Propane gas leak detector – 12V but is not working when the battery disconnect is off and not connected to shore power, so no power draw from this.

On mine there are only 4 wires that are connected ahead of the disconnect switch.

1) #14 wire orange/blue going to the breakaway switch.
2) #10 wire Black going to the Lippert remote receiver to power the board and relays.
3) #10 wire Black going to the 12V live terminal on the trailer hookup. Charge wire from TV.
4) #4 wire Black going to solenoid to power the hydraulic pump.

On the main panel in the stairwell the only thing receiving power is the slide switch (powered from the remote receiver), nothing else has power not even the tank monitors. I can turn on the DS flood light and hitch light using the remote but I cannot operate the awning using the remote. I can operate all of the hydraulic functions from the remote.
The automatic level up panel has power to it but must be turned on so would not draw any current unless it was actually turned on.

My determination is that the “only” thing that is drawing any current from my batteries while the disconnect is off and not connected to shore power is the Lippert remote receiver. It has a circuit board and a relay comes on when it is connected. I did not check the current draw to this device but there is sufficient draw to discharge the batteries in a fairly short period of time, depending on the condition of the batteries of course.

This information may be of little or no value to anyone else but it may give you some idea's if you want to check your own unit.

 

[vangoes]

Ed, that is good info to have. It certainly explains why trailers with the level up system batteries drain down even with the cutoff switch activated, The switch can serve its purpose on trailers without level but it is pretty useless on the ones with level up.

 

[Art-n-Marge]

My rig doesn't not have the disconnect switch from the factory. I have installed one of those big blade cutoffs that attach at the battery, so when I disconnect, EVERYTHING is disconnected.

When I towed trailers commercially and the disconnect was used while I was enroute, the brakes (and I would guess the breakaway) and the running lights on the trailer still worked (thank you, thank you, thank you), but the interior lights did not work. I suspect the slideouts did not work but I don't know about landing legs or propane alarms.

The goal of this thing is to limit the drain on the battery, but other than complete disconnection, there might be some trickle somewhere draining the battery and some things always available by battery. Thanks for posting your findings.

 

[DQDick]

Ed, mine works exactly as yours does.

 

[Irlpguy]

Actually the only time I have turned the disconnect switch to "off" was for experimental purposes. When I am at home the Monty is always plugged into shore power, when I travel I legally or not run my fridge on propane and 12V is required to do so. Draining the batteries has never been one of my concerns, I just wanted to know.

It would not be difficult to move the one wire that feeds the remote receiver to the switched side of the disconnect switch. This would work for me but may not eliminate all sources of drain in all cases. It is unfortunate there is not a wiring diagram for these units.

For me I am glad it was curiosity and not necessity that had me figure this all out, but now I know.