@ce72
I wired up the PWM to voltage converter as above, and found I needed the jumper to get an output. So I put the jumper in the 24v side and I was able to tune the voltage down to around 6.5v output, from this i added a "F" value on the M106 line of my config file to limit the output to the required 5v with full control.
I'm pleased to say all is now working great ๐ I will also order the required risistors and cap to try the other way, to make a cleaner install and not need the work around in the config.