Disconnect instrument cluster connectors "A", "B" and "C". See Figure. Start engine. Check AC voltage at terminal No. 9 of connector "B" (harness side). See Figure or Figure .
If AC voltage does not fluctuate, repair circuit between terminal No. 4 and ignitor No. 1. If AC voltage fluctuates, remove power source unit. See Figure. At circuit plate, check for continuity between the following terminals. See Fig 1.
- "A" and b7.
- "B" and b6.
- "C" and b8.
If there is no continuity, replace circuit plate. If there is continuity, check for continuity between the following terminals of connectors "A" and "S" (component side of each connector). See Figure, Figure, Figure and Fig 2 .
- A1 and S14.
- A6 and S15.
If there is no continuity, replace power source unit. If there is continuity, check resistance between terminals A4 and S13. If resistance is about 33 ohms, replace tachometer. If resistance is not about 33 ohms, replace power source unit.

Fig 1: Checking Circuit Plate Paths That Lead To Tachometer

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Tachometer Does Not Operate