Bizarre electrical issue

2chiefsRus wrote:

Janss wrote:
I have a built in digital clock in my motorhome by the bed. It seems whenever I turn on the gas furnace, it affects this clock. After the furnace starts running, the clock sounds one long beep and the time changes. This morning the display showed 0:02. Then awhile later it showed 52:08. Just weird. The clock display is fine before the furnace gets turned on. I'm plugged in to shore power.

Any ideas?

Did you buy this rv used? Maybe a previous owner wanted to know when the furnace kicked on because they were worried about using too much battery while drycamping?

What purpose would that serve? If someone was worried about the furnace starting I would think turning off the thermostat would be preferable to being woken up when it starts.

I'd bet that it's wired to the power for the furnace fan and the voltage drop causes the clock to reset.

Try removing fuses until you find the one that turns off the clock, reinstall the fuse.. does the clock make the same noise? Also see if the furnace will operate with that fuse out. If it's on the same branch circuit, you could try installing a capacitor and diode in line with the clock that might buffer the voltage drop enough to keep the clock operating. This link has good information, Discussion on capacitors to buffer voltage drop