Vent Fan on ceiling light switch T12RBST

[Lex3]

I just purchased my first a-frame last week, a 2023 T12RBST. I had my first chance since buying it to get in it and look everything over. I had a question about the ceiling vent fan: it seems that in order for it to work, the ceiling lights must also be on. I can think of occasions where I'd want the fan running but not the lights. Is it normal for them to grouped together on the same switch? If not, I will take it up with the dealer. If so, any suggestions on how to bypass this? Thanks

[kenandterry]

I can see where it’s the cheaper way to power the fan by tapping into the ceiling lights, because there’s existing wiring….both negative and positive, and I assume your fan is in very close proximity to at least one light.

In order for the fan to be powered independently, the manufacturer would need to run a separate “always powered” 12 volt feed.

To answer your question, no, it’s not normal for them to be grouped together on the same switch.

Unless someone else chimes in to confirm that their same model as yours works the same, it’s a DIY modification or you can have the dealer change it out. You just need to power the fan direct to 12 volts.

[pgandw]

The ceiling light switch near the door powers ALL roof mounted 12V items. And usually each roof mounted item has an individual on/off switch. The lights do, I'm not sure about the ceiling fan. This is done because all roof mounted items have to have power pass through a roof safety switch so that no power gets to the roof when the roof is lowered.

Older A-frames do not have the central switch, I have to turn on each roof item individually. The ceiling fan switch requires me to stand on tip toe to turn on/off, DW can't reach it at all. But all the ceiling lights and ceiling fan are on the same electrical circuit and fuse.

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Hyundai Palisade

[Lex3]

Thank you all for your help.

I went back and took a closer look at the lights, and discovered that they have switches in the middle of them that I had missed yesterday.

[jimmoore13]

This is normal.
Why? It's a 'belt and suspenders' approach to safety.

While your rig has a (typically) plunger style switch, either between halves of the flip-over sink or between the tub and the foldable roof, and this switch disables everything in the ceiling so that you don't close the roof with a light still on and scortch your duvet (or burn the camper down with same), these switches are trouble-prone, and it's not unusual for folks to wire around the switch if it's giving them trouble.

So the backup is the master switch for the lights and fan. Wouldn't you be mad if you got the rig all closed up and then heard the ceiling fan running or notice a light still on? This switch ensures you can turn off everything without having to erect the camper again. The same holds for popup campers...that's a real problem...crank up the roof, slide out the bed(s), turn off the light/fan!!!

Another thing. Whereas a light fixture, especially when incandescent, might get hot, a stalled ceiling vent fan motor is a fire waiting to happen. First you close the lid on it, then you suffocate its air intake with, say, a bed, and the motor will try to run, but the fan blades will stall. The motor windings melt down, and, if you're lucky, there's no fire.

The old fashioned breeze box fans were notorious for burning houses down because the fan would tip over on its back, there was no place for air to enter the back of the fan, and the motor would stall. Newer designs admit air to the back side of the fan blades even when the fan is flat on its back, so the motor won't stall completely.

Anyway, this is both a safety and convenience feature for your rig. Operate your lights individually/manually...or use the master switch. But if you want to operate the ceiling vent fan with no lights on, you must turn off each light individually so the fan will continue to operate. Bonus points for the fact that this encourages you to save energy when boondocking by running only those lights that are necessary.