My HUD has a switch on the power line too. I discovered that if the vehicle is moving (speed in kph > 0) the RPM doesn't seem to matter. But if not moving, and RPM under about 500, it's lights out. Or "display flame out", whichever you prefer :).

Greg

Mark Webb-Johnson wrote:

I’ve got two.

The first doesn’t sleep (supposedly). It has a manual on/off switch on the OBDII power line.

The second supposedly goes to standby mode after a configurable time after “engine flame out” (love those Chinese google translations).

I’ll have a look at the second one (which is the one I like the most anyway) to see what it says about configurability (“flame out” rpm threshold, and time setting).

Regards, Mark