check your fuses for the tach not working....should be the gauge fuse in the kickpanael driver side feet....replace the fuses and if not blown its probably your dimmer switch. mines burnt out when i installed my gauges over the weekend...climate and gauge lights shut off as soon as i turn headlights on. u can check to see if its the dimmer switch by taking that pael off, disconnecting the dimmer and jump the white/black wire with the white/green wire and lights should be on..hope that helps