No Load Test
- Connect a voltmeter and ammeter to charging circuit. See Fig 1. Check amperage and voltage with engine running at 2000 RPM. On models with external contact point voltage regulators, voltage should be 13.8-14.8 volts.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- On models with external IC type voltage regulators, voltage should be 14.0-14.7 volts on Land Cruiser, Pickups and 4-Runner with gasoline engines. On all other Toyota models, voltage should be 13.8-14.4 volts. On all models, current draw should be less than 10 amps.
- For further testing procedures for Toyota models with internal IC regulators, proceed to step 4). To further test Toyota models with external IC or contact point type regulators, proceed to TERMINAL "F" VOLTAGE TEST .
- If voltage reading in step 2) was above the specified range, replace IC regulator. If voltage reading was less than specified range, run engine at idle. Connect terminal "F" (located inside rear of alternator housing) to ground.
- If voltage reading now climbs to within specified range, replace IC regulator. If reading remains below specified range, replace alternator.