If you switch to 480p mode they may work over HDMI. it can't be connected to the switch/splitter, only connect directly to the TV, monitor, projector. This adapter not support for Wii Mini.
eBay
For Wii To HDMI-compatible Adapter Converter 3.5mm Audio For PC HDTV Monitor 1080P 720P Wii2 To HDMI WII2HDMI Converter Adapter
Aliexpress UK
1 x Wii to HDMI Converter. Video and audio in full digital HDMI format, no transmission loss! Output: HDMI Connector. Input: For Wii AV Connector. Supported Video input Mode: Includes all the display modes of the Wii console (NTSC 480i, PAL 576i).
eBay
For Wii To HDMI-Compatible Adapter Converter 3.5mm Audio For PC HDTV Monitor 1080P 720P Wii2 To HDMI WII2HDMI Converter 7 sold
Aliexpress UK
1x 1m HDMI Cable. Cable length: 1m. Supported HDMI output mode: Outputs purely digital HDMI video/audio signals. 1x Wii to HDMI Converter/Adapter. Input Connection: Wii AV Multi-Output. Outputs: HDMI port and 3.5mm stereo audio jack.
eBay
XIKCU Support Full HD Wii To HDMI-compatible Adapter Converter 3.5mm Audio For PC HDTV Monitor 720P Wii2 Adapter Converter
Aliexpress UK
The adapter cable supports 1080P and 720P signal output, can be very good adapter to play most of the high-definition video, clarity switch can be adjusted 720P and 1080P resolution;. only support RCA to HDMI, does not support HDMI to RCA use.
eBay
Support Full HD 1080P Wii To HDMI-Compatible Adapter Converter 3.5mm Audio For PC HDTV Monitor 720P Wii2HDMI Adapter Converter
Aliexpress UK
Descriptions: YPbPr to HDMI Converter, which is designed to convert analog audio from components such as DVD player/ game box and convert it to HDMI signal. It allows users to enjoy their larger images and videos on their desired display. With this item, home theater devices can be easily connected to HDMI display for video and audio experience. Features: Allows you to connect YPbPr HDTV sources to an HDMI display; Analog Audio onto the video signal for HDMI video and audio; Supports HDTV/YPbPr; Supports 165MHz/1.65Gbps per channel(6.75Gbps all channel)bandwidth; Supports 8bit per channel(24bit all channel)deep color; Package contents: Ypbpr component to HDMI converterX1 USB power cable X1.
eBay
50pcs/lot for Wii to HDMI-Compatible Adapter Converter Support Full HD 720P 1080P 3.5mm Audio Wii2HDMI Adapter for HDTV
Aliexpress UK
Connect the RCA/ AV cable to input port. 1 x AV to HDMI-compatible Converter (adapter not included). Connect the HDMI cable to output port.
eBay
XIKCU Support Full HD Wii To HDMI-compatible Adapter Converter 3.5mm Audio For PC HDTV Monitor 720P Wii2HDMI--Compatible Adapter
Aliexpress UK
RCA to HDMI Converter supports connecting HDMI capture card (note that we do not include HDMI capture card). 3, only supports RCA to HDMI, does not support HDMI to RCA use. Input: RCA, Output: HDMI; Converts Analog Composite Input to HDMI 1080p or 720p Output.
eBay
RCA to HDMI Adapter AV to HDMI Converter Composite to HDMI Converter for PS1/2/3 Xbox N64 WII VHS VCR Blue-Ray DVD STB Adapter
Aliexpress UK
Seamless Wii to HDMI 1080P Adapter. Full Digital Output: Connects seamlessly to the standard Wii video port and HDMI port, converting your video and audio output to a stunning HDMI format. Exceptional Video Quality: Advanced signal processing ensures great precision with vibrant colors and crisp resolutions up to 1080P.
eBay
Scart to HDMI converter 3-in-1 composite AV S-video Scart to HDMI cable converter Scart RCA in to HDMI out for wii DVD HDTV
Aliexpress UK