Optimal Place to Situate and Splice in a Switch to Disable All Jacks?

[CedarForks]

Ideas will be appreciated...

[Overland]

Is this for security?  I guess the easiest place would be at the DC bus bar.  Looking at your other post, you could do some 30A DC breakers there and accomplish both things at once.

 

If you wanted something easy to get to, but still hard to find, you could drill through the inner hull there and mount the breakers under the lip for the bed.  Then you could just reach under and flip them, yet they'd be out of sight.

[mountainoliver]

I added a battery master disconnect switch under the dinette seat. I didn’t want to drill a one inch hole so I took out the USB outlet and used that hole for mounting. I grouped all three of the jack feed wires together and used no.6 welding cable as a main feed. Hopefully the photos show up below.

[John E Davies]

There are three fat fused yellow wires coming off the DC bus under the street side bed, one runs to each jack motor.

 

Install a 12 volt 30 amp relay in EACH circuit between fuse holder and the bus strip.

 

https://www.amazon.com/ONLINE-LED-STORE-Waterproof-Harness/dp/B01N66W2XF

 

Run the three relay ground wires to a nearby ground.

 

Run the three power (control) wires for the relays to one of the single SPST switch terminals.

 

Run a fused (5 amp would be good) 12V power wire to the other terminal of the switch.

 

When you flip the switch on, power flows to the relay coils, energizes them "Kachunk!" and allows all three jacks to work.

 

Switch it off, and all jacks are stone dead.

 

Do not try to do this with one switch but no relays, the current flow is way too high. But DC breakers as suggested above would also work. The downside of adding relays is that there could be a failure that prevented one jack from working. If that happened you would have to bypass the failed relay and put that jack circuit back the way it was. Or mount a spare relay right next to the other three and swap it out, which would be a two minute job.

 

OR just remove all three fuses from the inline holders when the jacks are not needed.

 

Adding relays sounds like a lot of work but it would be a simple and reliable mod. No worries if done correctly. This would be a great $100 Hidden Security option for the factory to offer.

 

John Davies

 

Spokane WA

 

 

[mountainoliver]

Or simply add a 15$ 300 amp battery master disconnect switch with removable key. The bad guy will look for hours trying to figure it out.

[John E Davies]

Or simply add a 15$ 300 amp battery master disconnect switch with removable key. The bad guy will look for hours trying to figure it out.

 

What if you want to disable the jacks for when you are gone but don’t want to kill all the appliances and lights? A master switch is fine if you want the entire trailer completely dead. I think CedarForks was looking for a way to quickly kill just the jacks....

 

John Davies

 

Spokane WA

[BackofBeyond]

Adding relays sounds like a lot of work but it would be a simple and reliable mod. No worries if done correctly. This would be a great $100 Hidden Security option for the factory to offer.

 

John's mod is well thought out and  sound way of achieving the desired result. It may be beyond the skills of some, but switching a low amp relay on and off is a much saner way of powering the jacks on and off, without affecting any other system.  One could also use one relay to power a buss - which fed the jack circuits,  or use a 3 pole relay or, well you get the idea, several solutions, I tend to choose the less complex.

 

I suppose the simple solution is to just remove the fuses.

 

I'll just use my hitch lock for security. At some point, short of an armed guard, crooks are gonna do what they do, hopefully they move on to an easier target.

 

RB

[CedarForks]

I'd better disclose the real reason for looking for a disconnect solution: rambunctious grandchildren -- who cannot resist making a three ton egg move with a mere fingertip, especially when grandpa has just achieved a perfect level and has temporarily left ...

[mountainoliver]

Sorry, I meant that the disconnect switch is only for the jacks. I just used the term that is used on the packaging for the switch. The manufacturer calls it a master disconnect switch because it is typically used for race cars and boats etc to completely disconnect the batteries from the vehicle. I choose this because they are cheap, can handle high amp loads, readily available, and reliable because their construction is so simple. I may have misunderstood the original question. Also, the amp draw through the switch is only what one jack motor would draw. I only operate one jack at a time. I feel that the 300 amp capacity master switch will more than handle one jack at a time or even all three at once. I also forgot to mention that the red key is removable so unauthorized use is difficult to say the least. I always “disconnect “ the jacks when camping or any time the camper is unattended to prevent the jacks from “accidentally” being moved. Wink

[Mainiac]

Maybe that master disconnect switch should be mounted right up front. Somebody turns it to on, a relay activates a siren sounds for three minutes or so. Shutting it off would not silent the alarm. The real switch to activate the jacks could be inside the main door?