hmm.....
Well, that reply was somewhat better than what I got from the local Lexus dealer; they said it could be the alternator (?) Doesn't make sense to me unless there is a deliberate feature (i.e. undervoltage condition) causes the gauges not to light. Sounds a bit dangerous, though, and...
The gauges and their lights in my '98 GS400 stopped working. Checked fuses under dash (especially 10A GAUGE fuse) and under hood; all look good. Car runs and other lights work (even warning lights on dash when you first turn key ) but tach needle doesn't move nor does it or speedo gauge light...