Well this is embarrassing (not for me, for Jayco). Quick backstory: we purchased our 24BH new (factory order) in 2021. Day 1 PDI did not flag any electrical issues. My wife and I walked through the TT with a complete checklist and each did our own independent test of every component we could find including the heated tank pads. Our day 1 inspection revealed that the slide did not work on battery power, only shore power which then revealed a whole host of other issues. Dealer replaced the entire breaker panel and circuit board which fixed the issues. Day 3 - we were on our way. Again, this was back in January 2021.
Fast forward two and a half years and it's getting cold here in Central Virginia. Since we travel in the winter, it was time to start turning the heated tank pads for a few of those below freezing nights. Well, I went out to check on the TT after having the pads "on" for a day and I noticed that the LED lighted switch had gone off. Checking the panel, nothing was tripped or blown. Flipped the switch a few times and I got no feedback.
Pulled the lighted switch and tested voltages. Everything seemed to be in order. Three wires - hot (line), load, and neutral. 12 volts at the line and switch. Googled the switch which was a Carling 18 volt lighted 1948 R and found the pinouts. I noticed that something was wrong on the wiring and pinouts. Traced the wires to a relay under the stove. Googled the relay NT90HCE12CB DC12v 30amp 6 pin AC120v.
From what I can tell, the relay is powered by the line of the circuit that runs the GFCI outdoor outlet. The relay runs to the 12v DC switch which, when engaged, activates the relay which then feeds 120v to the four plugs of the heated tank pads. Well, the way that this was wired is the lighted switch would light up but it would not activate the relay. For two years, all I was doing was turning on a pretty red LED. Thinking back, I never heard the relay engage or disengage when the switch flipped. Only the switch clicking.
I pulled a lighted switch from my shop and wired it up per the spec sheet. I flipped the switch and "snap" - the relay clicked when activated. Flipped the switch again and "snap" - the relay clicked when deactivated. Flipped it a few times on the volt meter and confirmed on = 120volts, off = 0 volts.
Lesson learned: when you think something is working as it should, give it a double check even if it means opening up the underbelly and feeling the tank pads or tracing wires to a relay. Go as far as marking it up too because, at some point, we are all going to suffer from CRS and won't remember what that non-labeled junction box is for.
Given the electrical issues we had on day one, I'm not surprised that this too was wired incorrectly. But hey, better find it now than never and I can enjoy my warm black tank discharge on those cold Virginia days.