4. SOLAR SENSOR Check sensor voltage. 0.3 — 0.5V (In Daylight) Double Vacuum Valve (DVV) (DVV is located on heater unit) INSPECTION OF DVV CHECK VACUUM CIRCUIT CONTINUITY BY BLOWING AIR (a) OFF state All circuit should be closed. (b) Apply 12 volts to the positive (+) terminal and ground terminal T1. There should be continuity between B and C at this time. (c) Apply 12 volts to the positive (+) terminal and ground terminal T1. There should be continuity between A and B at this time. If a problem is found, replace the DVV. Water Temperature Switch INSPECTION OF WATER TEMPERATURE SWITCH CHECK WATER TEMPERATURE SWITCH OPERATION (a) Disconnect the 1-pole connector from the water temp. switch. (b) Check continuity between the water temp. switch and ground as follows. Coolant temp. A B Less than 30°C (86°F) CONTINUITY CONTINUITY From 30°C (86°F) to 50°C (122°F) NO CONTINUITY NO CONTINUITY More than 50°C (122°F) NO CONTINUITY NO CONTINUITY If a problem is found, replace water valve. WATER TEMP. SWITCH A (30°C) SWITCH B (50°C)