TrailManor Owner's Forum - View Single Post - Master Battery Switch and Electric Tongue Jack

07-09-2008, 09:22 PM

I posted some pictures not too long ago, but I don't know how to find the thread where I posted them. I can describe what I did.

I used a 4 position switch that I purchased at the local West Marine store. I figured that a marine switch could tolerate moisture better than a regular switch. The switch is white and red, about 3 inches sorta rounded off square. Positions are off, battery 1, battery 2 and both batteries.

I used marine grade stranded tinned wire of the same guage as was already on the TM. I have a 30 amp fuse on each battery and another 30 amp fuse for the switch. All current goes through two fuses. I'm not sure that is proper, but that is what I did.

I found an electrical box for outdoors that has a flip up cover. It is not sealed in the back, so I cut a piece of sheet aluminim to close of the back with some caulk. For fear of the wires on the back of the switch making contact with the sheet aluminum there is a sheet of plastic between the aluminum and the switch. There is a full circle terminal lug on the end of each wire, that is crimped and then soldered. I don't trust just a crimp with all that vibration. A short from a loose connection would be very bad.

I bent a pair of aluminum bars into a J shape. They each attach at two points, the top machine screw is attached to the angle iron that supports the front endge of the floor. The short front edge of the J attaches to the back side of the rear battery support piece of angle iron. I had started with an L shape and bolted it to the bottom of the battery support, but I scraped in a driveway and sheared off the machine screw.

I used machine screws to go through, in this order, the switch, the plastic sheet, the aluminum sheet, the electrical box, the J brackets.

Rain will not get to the switch because it is under the front of the TM, near the front drains, but inside the frame.

I know that when the switch is aligned vertically it is either on both batteries or no battery. I turn on an external light to know the difference.

I have to bend down to get to the switch. There is some risk that I could forget to turn it on and then I would not have an operating breakaway brake. I just am very careful. If in doubt I turn on one of the three outside lights to verify that I have power from the batteries. The TM must be unplugged from the TV to verify this otherwise it would just draw power from the truck.

When the TM is disconnected from the truck and the switch is off then there is no 12 volt power anywhere in the TM. This includes the fridge when it is set to 12 volts. This is what allows me to control the fridge on or off from the outside. It also eliminates all parasitic loads when the TM is closed in storage.

I hope that helps.

07-09-2008, 09:22 PM	#7
PopBeavers Guest Posts: n/a	I posted some pictures not too long ago, but I don't know how to find the thread where I posted them. I can describe what I did. I used a 4 position switch that I purchased at the local West Marine store. I figured that a marine switch could tolerate moisture better than a regular switch. The switch is white and red, about 3 inches sorta rounded off square. Positions are off, battery 1, battery 2 and both batteries. I used marine grade stranded tinned wire of the same guage as was already on the TM. I have a 30 amp fuse on each battery and another 30 amp fuse for the switch. All current goes through two fuses. I'm not sure that is proper, but that is what I did. I found an electrical box for outdoors that has a flip up cover. It is not sealed in the back, so I cut a piece of sheet aluminim to close of the back with some caulk. For fear of the wires on the back of the switch making contact with the sheet aluminum there is a sheet of plastic between the aluminum and the switch. There is a full circle terminal lug on the end of each wire, that is crimped and then soldered. I don't trust just a crimp with all that vibration. A short from a loose connection would be very bad. I bent a pair of aluminum bars into a J shape. They each attach at two points, the top machine screw is attached to the angle iron that supports the front endge of the floor. The short front edge of the J attaches to the back side of the rear battery support piece of angle iron. I had started with an L shape and bolted it to the bottom of the battery support, but I scraped in a driveway and sheared off the machine screw. I used machine screws to go through, in this order, the switch, the plastic sheet, the aluminum sheet, the electrical box, the J brackets. Rain will not get to the switch because it is under the front of the TM, near the front drains, but inside the frame. I know that when the switch is aligned vertically it is either on both batteries or no battery. I turn on an external light to know the difference. I have to bend down to get to the switch. There is some risk that I could forget to turn it on and then I would not have an operating breakaway brake. I just am very careful. If in doubt I turn on one of the three outside lights to verify that I have power from the batteries. The TM must be unplugged from the TV to verify this otherwise it would just draw power from the truck. When the TM is disconnected from the truck and the switch is off then there is no 12 volt power anywhere in the TM. This includes the fridge when it is set to 12 volts. This is what allows me to control the fridge on or off from the outside. It also eliminates all parasitic loads when the TM is closed in storage. I hope that helps.