Hello all,

I almost have all of my answers to start my Virtual Instrument cluster project.
I am going to design a circuit board to connect to an original (second hand) cluster. Then I'll mount a (touch)screen in the place where the dials are now and mount a bar with lights on the top of the cluster to get all the warning lights and indicators, because it is almost impossible to get that also from the OBD2 protocol/CAN protocol. On the screen it will show all my dials, gauges and graphs, like Speed, RPM, Coolant temp, fuel level, turbo boost pressure, fuel level, etc. Even navigation will be shown on the screen.

All of that info I will retreive from the OBD2 port and protocol. This is why I have the following question:
- My virtual dashboard is connected to the OBD2 port and it will use that Protocol. When I have my MOT or other maintenance, they need acces to the OBD2 as well. If I split the OBD2 port with a "Y" cable (all wires populated) and plug my OBD2 dongle (like OBDlink, ELM327, etc.) in and leave the other end available for the mechanics, will this work?

It would be a pitty if I/the mechanic has to disconnect the instrument cluster every time some diagnostics have to be done on my car.

I cant remember the details why having read about it years ago,as i wanted to do soomething simular, but i think you can only use one at a time

@htevents Having recently read up even more, I think one arm can be Bidirectional ie read and write but a second can only sniff the canbus I am about to buy a spliter for this precise purpose once i get my canbus sniffer working (arduino and canbus shield built in)

Now using a spliter recording data with MES and on second leg an arduino reading canbus data and saving to SD card.

htevents said:

and mount a bar with lights on the top of the cluster to get all the warning lights and indicators, because it is almost impossible to get that also from the OBD2 protocol/CAN protocol.

Click to expand...

It you’re going to all the effort to build a custom unit to read the canbus data, then presumably build your own custom touch screen UI into a display that you’re using to replace the dials, that level of work is very high already, you only need to connect the signals from the various warning lights to a microcontroller like a pi pico or a ESP32 and then feed the data into your custom unit to be able to have all the warning lights display on the screen as well.

Will this work with a car that’s not on your site in the select vehicle section?