THERMO Time Switch
- Remove thermo time switch and install plug to prevent loss of coolant. Cool thermo time switch by immersing in cold water. Connect positive wire of switch to a test lamp and battery positive terminal. Connect battery negative terminal to switch body. Test lamp should glow. See Fig 1 .
- Insert thermometer in water and gradually heat water. Test lamp should glow until temperature reaches 88-102°F (31-39°C). If switch does not respond as outlined, continue testing as follows:
- Cool switch to temperature below that stamped on side of switch. Connect ohmmeter between terminals shown in table and note readings. Heat switch to temperature above 104°F (40°C) and again note readings in table. If readings are not to specifications, replace thermo time switch.
THERMO TIME SWITCH RESISTANCE
| Temperature: °F (°C) | Terminal Nos. | Ohms |
|---|---|---|
| Below 86 (30) | G & Ground | 25-40 |
| Below 86 (30) | W & Ground | 0 |
| Below 86 (30) | G & W | 25-40 |
| Above 104 (40) | G & Ground | 50-80 |
| Above 104 (40) | W & Ground | 100-160 |
| Above 104 (40) | G & W | 50-80 |