System Testing

Start engine. Ensure coolant temperature is below 109°F (43°C). Using a voltmeter, ensure voltage is present between positive terminal and body ground. See POSITIVE TERMINAL WIRE COLORS table for correct wire color application. Ensure voltmeter probe is inserted from rear of connector. See Fig 1.

POSITIVE TERMINAL WIRE COLORS

Application

Wire Colors

Corolla (Carbureted) & Corolla FX

White/Red

Pickup

⁽¹⁾

Tercel Sedan

White/Red

Tercel Wagon

White/Blue

⁽¹⁾	Wire color not available.

Warm engine to above 131°F (55°C). Ensure no voltage is present. If no problem is found, system is okay. If system fails to operate as specified, perform following component tests.

Fig 1: Checking Cold Mixture Heater