How to Replace a Dual Battery Switch

What You'll Need
Dual battery switch
Philips screwdriver
Waterproof caulking

When it comes to having fun on a boat, the dual battery switch has a lot to do with it. This switch will let you turn from one battery to another without having to go without electrical power for too long. When the first battery starts to fail, then you can simply turn the switch to the other battery for continued service. There are times when you want to replace your worn dual battery switch for a new one, or just move it to a new location. Here are the steps to take to replace your dual battery switch.

Step 1 - Disconnect Battery Cables

Before beginning any type of work on your boat's electrical system you should always disconnect the battery cables. Do not limit this just to the negative battery cable. You can still have an accident when the negative terminal brushes up against something metal and can complete the circuit. You are much better off when you disconnect both of the cables to ensure against any type of accident. 

Step 2 - Remove Switch Cover

Using your Philips screwdriver you can remove the dual battery switch cover to get at the wires underneath. Depending on the actual brand of battery cover you have, you may only need to push on a tab to remove the cover. 

Step 3 - Disconnect Wire to Solenoid

There are going to be two types of wires on your dual battery switch. Two of the wires are going to be running to your batteries. The other type is going to be running to the solenoid where your battery gets its starting power. Disconnect this wire by unscrewing the small set screws. 

Step 4 - Disconnect Battery Wires

Using your screwdriver again you will need to remove the set screws that hold the battery cables to the battery switch. Remove these and set them aside to install in the new switch. Take care not to break any of the wires off if these wires have been in the boat for a long period of time. If they look to worn you may want to change the wires before you finish with the dual battery switch replacement. 

Step 5 - Remove Switch from Mount

If you have your switch mounted on a bracket, or simply drilled into a panel, you will want to remove it at this point. Unscrew it from the panel and set it aside. 

Step 6 - Install New Dual Battery Switch

Place the new battery switch on the place where the previous one had been. If it is the same model you may be able to use the same mounting materials. If not, simply remove the bracket and replace it with the new one. Screw the new switch into place.

Step 7 - Connect All Wires

Thread the wires back into their positions inside the battery switch and make all the connections. Make sure the wires are secure and making good contact at all points.

Step 8 - Replace Cover

Once the wires are all connected you can replace the new cover and fasten it securely. Use a little bit of waterproof caulking around the exterior of the switch box to protect if from any water.