THERMO Time Switch: Renault
- Remove thermo time switch and install plug to prevent loss of coolant. Cool thermo time switch by immersing in cold water. Connect Black wire to a test lamp and battery positive terminal. Connect battery negative terminal to switch body. Test lamp should glow. See Fig 1.
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- 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 terminal "G" and switch housing (ground). Reading should be 25-40 ohms. Connect ohmmeter between terminal "W" and ground. Reading should be 0 ohms. Connect ohmmeter between both terminals. Reading should be 25-40 ohms.
- Heat switch to temperature above 104°F (40°C). Connect ohmmeter between terminal "G" and switch housing (ground). Reading should be 50-80 ohms. Connect ohmmeter between terminal "W" and ground.
- Reading should be 100-160 ohms. Connect ohmmeter between both terminals. Reading should be 50-80 ohms. If switch does not respond as outlined in steps 3 and 4, replace thermo time switch.