That yellow LED on your Georgetown house battery switch? It may be lying to you.

[NXR]

My 2020 Georgetown has a self-centering spring-loaded rocker switch to turn the house batteries on and off. You momentarily press the top of the switch to turn the house batteries on or momentarily press the bottom of the switch to turn the house batteries off. After you release the pressure the switch returns to the center position.

So there is no way to look at the house battery switch and tell if the house batteries are turned on or off. The switch has a built-in yellow LED indicator that is supposed to tell you that the house batteries are turned on but it is not wired that way.

While troubleshooting an electrical problem I discovered that the yellow LED on the house battery switch does not tell me that whether the house batteries are turned on and therefore connected to the coach electrical system and thus charging when plugged into shore power. (I did not test on generator but it should behave the same way as shore power.)

That house battery switch yellow LED is actually telling me that the coach's 12 VDC bus is powered up somehow. If I'm plugged in or running off the generator then the coach's 12 VDC bus is powered up by the converter.

Similarly, the Precision Plex touchscreen "levels" screen has a battery indicator complete with the changing horizontal bars and a voltage reading. The touchscreen is also lying because it, too, is reading the coach's 12 VDC bus voltage and not the house battery voltage when plugged in.

What's the difference, you ask?

If you have the house batteries turned off and plug in shore power, the coach powers up, the house battery switch yellow LED illuminates, and the Precision Plex touchscreen shows all is well with the house battery voltage.

But until you actually press the top of the house battery switch and hear the relays "clunk", the house batteries themselves are disconnected from the coach and not being charged.

Try it and see if yours works this way. My yellow LED was lit, the touchscreen said 13.3 VDC and the actual battery voltage at the house batteries was measured as 12.6 VDC. After I pressed the top of the house battery switch I head the "clunk" and the house battery terminal voltage increased to 13.3 VDC. There is no indicator to tell me that the house batteries were in fact not being charged.

I think I just figured out why my house batteries drop in voltage so fast...

Ray

[Mike60]

Great information Ray, Thanks