My off-road Starcraft 14RT came with two of those clamp on Light/fan units...
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These plug into the ceiling light assemble on ends of my POPUP trailer near the tent bed ends...
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Mine didn't last long. The fan part both went out in about 6 months. Fan just quit working. Mine also had the automotive type very hot incandescent bulb in them. They got very hot when being used... These are a great idea however clamping to the over head tent bed fabric support...
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I did not replace the light/fan combo unit with a like unit but got a couple of the O2COOL 11-inch AC/DC/D-CELL fans (WALMART) that really work well in all conditions...
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These plug into a 12VDC socket I have added to a cabinet on both ends of the trailer. The D-CELLS last along time as well.
As far as having lights for the tent bed ends I added a couple of 120VAC ROPE LIGHTS (LOWES) just behind the Valance Curtain up on the ceiling lip. These are my night lights and work just great for the tent beds ends when you pull the curtains...
These are plugged into my 600WATT PSWN Power Inverter Emergency 120VAC Power available for my 24/7 Power requirements from the battery. This circuit is always on and is available to use from a multi-tap 120VAC receptacle from the side of the cabinets top close to the tent bed ends on both sides of the popup trailer... Being Pure Sine Wave I never have to worry about what is plugged into them and going up in the infamous blue smoke...
Works great for us...
Roy Ken