When I turn my battery cutoff switch to "Off", there remains a parasitic draw on the batteries from various detectors, etc. I wish to remove this draw so that I can keep the 2 12 volt batteries fully charged when the trailer is not in use with a Battery Tender.There is a wire that is on the left side of the switch that causes this parasitic draw. Any reason I should not move that wire to the right side of the cutoff switch, thus fully isolating the batteries from the coach?See picture:

Best to fix immediately if not sooner.

That is a pretty big wire so there must be some other things on it besides the detectors. I would want to know what is on it before I would decide.

Trace the wire out and see where it goes first. It just may be on the wrong side of the switch.

The O-N-L-Y device not to be switched off with a master disconnect is a BILGE PUMP. If your rig has a propeller then it's time to stand back and review the options.

Any reason I should not rewire? | Good Sam Community

14 Replies

Winged_One
Explorer
Jul 01, 2015
Thank you all for the input. It has been very helpful.

The bar is connected to the output of the switch, and thus must feed everything else in the trailer (including slides, leveler, etc which do not work unless the switch is turned to "on"). Don't have an inverter.
MEXICOWANDERER
Explorer
Jul 01, 2015
kaydeejay wrote:
MEXICOWANDERER wrote:
The O-N-L-Y device not to be switched off with a master disconnect is a BILGE PUMP. If your rig has a propeller then it's time to stand back and review the options.
Not quite true - the trailer breakaway switch should have power at all times too.

Scooze me

Never heard of a towed unit referred to as a "coach" before. That's also the rrason for the propeller crack...
Gene_Ginny
Explorer
Jul 01, 2015
Winged One wrote:
...See picture:

Assembled late on Friday, 10 minutes before quitting time ... oops!
wnjj
Explorer II
Jun 30, 2015
Tom N wrote:
Easily solved by removing the negative battery terminal.

So long as you remember to reconnect it before towing it.
Tom_N
Explorer
Jun 30, 2015
Easily solved by removing the negative battery terminal.
DrewE
Explorer II
Jun 30, 2015
My guess, as others suggested, is that it's your brakes for the breakaway switch. Don't alter it if it is that.

Where does that bus bar next to the disconnect switch get wired into things—is it on the battery side of the switch, or on the switched side? If it's on the battery side, probably one or more of the wires leading off of the circuit breakers there goes to the detectors etc. that are causing the draw, and this particular circuit could somehow be switched over to the other side of the disconnect switch with more or less impunity. There are many other things that might be wired on the unswitched side of the shut-off switch for various reasons—slide out or entry step motors/controls, levelers, an inverter (mostly because of the large current draw which may overtax the contacts in the switch), the converter (so you can charge the battery with the shutoff switch off), the charge line from the truck connector....
kaydeejay
Explorer
Jun 30, 2015
MEXICOWANDERER wrote:
The O-N-L-Y device not to be switched off with a master disconnect is a BILGE PUMP. If your rig has a propeller then it's time to stand back and review the options.
Not quite true - the trailer breakaway switch should have power at all times too.
Toddupton
Explorer
Jun 30, 2015
Just make sure it does not go to the brakes. You don't want those off ever just in case you forget to turn it on before you leave.
GMandJM
Explorer
Jun 30, 2015
Yes, you can do that.

Keep in mind that batteries have a self-discharge rate effected by different things (temp, what they're sitting on, etc) so there's no guarantee that they will stay "fully charged" without the battery tender.

If you are using a BT, you might want to leave it as is since a little draw can be beneficial.

That looks like an awfully big gob of wire exposed from your connector, btw.
MEXICOWANDERER
Explorer
Jun 30, 2015
The O-N-L-Y device not to be switched off with a master disconnect is a BILGE PUMP. If your rig has a propeller then it's time to stand back and review the options.