Definitely check that, and the fuse in the yellow wire too (inside the filter block, there's a pop-off cover).

If you have a rio-car, then that's a slightly different matter; the mk2 would power itself from the accessory line if the fuse blew in the permanent on line (bad!) due to the diode between accessory & main power - which is there for home power situations (long story!).

The mk2a's power PIC is more intelligent though, and doesn't do this.

Hugo