Plumbing done!

[pvfjr]

When you use the freshwater tank, if you hear the pump cycling when no water is being used, then that's your clue you likely have a leak somewhere.

I forgot to add this to my bullet points! I knew if felt incomplete.

This really is key though. I've had the "wait, why did the pump just cycle" question reveal more issues than I can count over the years on many RVs or trailers. Had I been on city water, I would've ruined a lot more flooring.

 

[pvfjr]

I can PEX both sides, but I’m not sure I can pull hard enough to pull the overhead loose and pull in 1/2 PEX in its place.

1/2" PEX feels a little big to me. That's a standard size for servicing a few appliances in residential, but I use considerably less water on the RV's kitchen sink. I'm not sure where everyone else lands on this, but I do a lot of boondocking, and try to be pretty conservative with water. I use fairly low-flow aerators since I can't count on everyone in the family washing hands or brushing teeth quickly and with minimal water usage. Since that overhead line only serves one sink, 3/8" is good enough for me.

Another consideration is hot water arrival time. With the greater volume of cooled-off water in the hot-water line (a 1/2" line holds 82% more water than a 3/8" line), it takes longer for the hot water to make it to the tap (for a given aerator/regulator flow rate). That's more time wasted, but also more cold water wasted waiting for the hot water to show up.

 

[Christo]

1/2" PEX feels a little big to me. That's a standard size for servicing a few appliances in residential, but I use considerably less water on the RV's kitchen sink. I'm not sure where everyone else lands on this, but I do a lot of boondocking, and try to be pretty conservative with water. I use fairly low-flow aerators since I can't count on everyone in the family washing hands or brushing teeth quickly and with minimal water usage. Since that overhead line only serves one sink, 3/8" is good enough for me.

Another consideration is hot water arrival time. With the greater volume of cooled-off water in the hot-water line (a 1/2" line holds 82% more water than a 3/8" line), it takes longer for the hot water to make it to the tap (for a given aerator/regulator flow rate). That's more time wasted, but also more cold water wasted waiting for the hot water to show up.

Note, the selection of SharkBite fittings is more limited in 3/8" than 1/2". Flair-it fittings might be a good alternative for some of the fittings; they have a lot of 3/8" stuff.

 

[Christo]

Here's the 1/2" to 3/8" Flair-It coupler that saved the day, along with a photo showing that the drain knob is reachable without removing the cabinet. Note also the (gasp) Chrysler rear window defogger timer/switch I use to temporarily turn on the water pump from the bathroom. And oops, looks like I reinstalled the cover plate upside down

 

[pvfjr]

Note also the (gasp) Chrysler rear window defogger timer/switch

Wait a minute, is this a self-contained timed relay that draws no power in standby? What are the applications? I love finding stuff like that--stupid cheap in the junkyard. Half the time they don't even want to write up an invoice.

 

[Christo]

Wait a minute, is this a self-contained timed relay that draws no power in standby? What are the applications? I love finding stuff like that--stupid cheap in the junkyard. Half the time they don't even want to write up an invoice.

Yes, not sure what vehicle it came from but it's a rear defogger switch with an integrated 10-15 minute timer. It also has a light on the switch that illuminates when on. It's one of those switches that springs back to center automatically if you rock it in either direction (on/off). There's a Chrysler pentastar logo on it. I can look for a part number if you need it.

 

[pvfjr]

Hmm, maybe the sideways heat arrows with the light at the top edge? It's hard to make out in your photo, but I think this one matches more closely.

 

[Christo]

Hmm, maybe the sideways heat arrows with the light at the top edge? It's hard to make out in your photo, but I think this one matches more closely.

View attachment 16927

Bingo! What’s the part number?

 

[pvfjr]

5209985.
Says it's for 80s Charger, Omni, Lebaron. Pictures show 4 terminals on the back, but a '87 Lebaron diagram shows 5. Hmm...

 

[RF_Burns]

Yes, not sure what vehicle it came from but it's a rear defogger switch with an integrated 10-15 minute timer. It also has a light on the switch that illuminates when on. It's one of those switches that springs back to center automatically if you rock it in either direction (on/off). There's a Chrysler pentastar logo on it. I can look for a part number if you need it.

I ran a wire off the bathroom lights to a cube relay wired across the Pump switch. The pump comes ON whenever someone enters the bathroom and turns ON the lights. The pump stays ON until you leave the bathroom and turn OFF the lights.
The main Pump switch light also turns ON to let others know the bathroom is occupied... or the bath lights have been left ON!
JWID.