Battery Selector Switch

When this truck was built, I had wanted to install a dual battery selector switch just like you would find in a modern piece of fire apparatus. I did not do so at the time due to time and cost as well as trying to figure out how to make it fit. The dual battery selector switches that I’ve seen on the fire trucks I’ve been in, are very large, obviously, in order to safely handle the amperages that pass through them. Then, in the fall of 2006, when I took the truck to Madison, Indiana, to visit one of the truck’s sponsors, RKO Enterprises, I found a product from Bep Marine in RKO’s inventory that solved the space and cost issues. It’s a compact dual battery selector switch that was a perfect fit in the electrical compartment on Project Responder.

The first step in this process was to connect the battery cables to the selector switch. Using 3/8” ring terminals, the three cables were attached and set to run through one side of the selector switch housing. Then the cables, without terminals, were passed through the holes drilled in the back side of the compartment. Using the same kind of compression fittings as was used in the inverter installation, the battery cables were then fully sealed. The cables themselves were 1/0 gauge cable. Once the cables were through and the battery selector switch moved into place, four holes were drilled in the floor of the compartment to mount the selector switch permanently.

The next procedure was to remove the existing negative battery cables. After removing the driveshaft and removing the battery box cover, the “original” battery cables were disconnected and removed. At this point, ring terminals were crimped onto the ends of the new cables and connected to the batteries, and to the frame. After reinstalling the battery box cover and the rear driveshaft, the installation was complete. This came at a perfect time as well since the truck was scheduled to appear at the St. Louis Auto Show in January 2007 and a requirement of the show, being indoors, is that the batteries must be disconnected. The entire project took about six hours, but it was well worth it. Now, I’ll never have to be concerned about the batteries draining when the truck is parked for extended periods of time. Thanks to Keith at RKO, another upgrade is successful.