GMC Battery Saver

Several GMCers complained that when they were dry camping in cold weather, occasionally their furnace would continue to run until their house battery went dead. They asked if there were a way to control the furnace by shutting it down before the battery is completely dead, because this usually happens when one is sleeping or away from the coach for an extended period.

In response to that request, I tested a product called a "Low Battery Protector" and discovered it would work fine if we added another component. That's because the battery protector device is rated at max 5 amps and our coach circuitry requires over 10. To make this circuit work I put the battery protector device together with a 30 amp automotive relay and installed the circuit into my 77 Kingsley in the bathroom, where the 12 volt house circuits buss is located. That's in the cubby hole next to the toilet paper holder.

Due to requests from 19 GMCers I put together some systems and shipped them out several weeks ago. I am waiting for feedback from them to learn how the installs went in their coaches.

I have a 77 Kingsley. In the bathroom there is a power distribution panel that supplies 12 volts to the furnace. Basically the circuit monitors the 12 volt level (indicated via a green led when the voltage is ok) and shuts off the power to the furnace whenever the voltage goes down to under 12, (indicated with a red led). Power is not restored again to the furnace until the battery voltage gets back to 12. Power is also removed from the auxiliary fan, if that option is installed in your coach.

Here is a shot of the completed installation in my 1977 Edgemont. (Others will install in their respective electrical cabinets)

This is it. The circuit has been designed, installed and tested and works like a champ.

Total cost is $55.00 which includes $5.00 for priority mail in the lower 48.

To order, contact:

Bob Sobrito
rssbob@cox.net
9927 Lemon Ave
La Mesa, Ca 91941
619-460-2145