BODY ELECTRICAL SYSTEM – COMBINATION METER BE–47 TACHOMETER INSPECTION INSPECT TACHOMETER ON–VEHICLE (a) Connect a tune–up test tachometer, and start the engine. NOTICE: Reversing the connection of the tachometer will damage the transistors and diodes inside. (b) Compare the tester and tachometer indications. If error is excessive, replace the tachometer. RPM (DC 13.5 V, 25˚C (77˚F)) Standard indication (rpm) Allowable range (rpm) 700 630–770 1000 915–1115 2000 1920–2220 3000 2890–3350 4000 3940–4400 5000 5025–5425 6500 6650–6950 7000 7025–7625