Pete 386 Electrical Issue gauges losing power

[Nilao]

So do the gauges just die or do they seem to go into a constant sweep mode with the dpf lights blinking on and off.

My 2009 387 had a similar issue and it was the ignition relay in the fuse box out on the passenger side firewall.

The start relay and ignition relays are identical so you could swap them around just to test that theory.