FixVault

Tachometer Testing

  1. Disconnect Yellow/Blue wire from ignition coil. See IDENTIFYING TACHOMETER CIRCUIT illustration. Connect a signal generator and tachometer tester between Yellow/Blue wire and ground.
  2. Operate test equipment in accordance with manufacturer instructions. Compare tester and tachometer. See TACHOMETER SPECIFICATIONS table. If indications are within allowable range, fault may be ignition related. If indications are not within allowable range, replace instrument cluster.
TACHOMETER SPECIFICATIONS

Standard Indication (RPM) Allowable Range (RPM)
1000 1000-1050
2000 2000-2050
3000 3000-3050
4000 4000-4050
5000 5000-5050
6000 6000-6050
Fig 1: Identifying Tachometer Circuit
G90A08299