Coolant Temperature Gauge

Gauge Test

IOTE: Refer to page 23-135 for the wiring description f the coolant temperature gauge circuit diagram.

Check the No. 15 (10 A) fuse in the under-dash fuse box before testing.

Make sure the ignition switch is OFF, then disconnect the YEL/GRN wire from the temperature gauge sending unit and ground it with a jumper wire.

3. Turn the ignition switch ON.
Check that the pointer of the temperature gauge starts moving toward the "H" mark.

CAUTION: Turn the ignition switch OFF before the pointer reaches "H" on the gauge dial. Failure to do so may damage the gauge.

• If the pointer of the gauge does not move at all, check for an open in the YEL or YEL/GRN wire. If the wires are OK, replace the coolant temperature gauge.

•   If the gauge works, inspect the sending unit.
Sending Unit Test
1. Disconnect the YEL/GRN wire from the sender.

2. With the engine cold, use an ohmmeter to measure resistance between the positive terminal and the engine (ground).

3. Check the temperature of the coolant.

4. Run the engine and measure the change in resistance with the engine at operating temperature (cooling fans come on).

Temperature	56°C (133°F) (Engine cold)	85°C (185°F) 100°C (212°F)
Resistance (S2)	142	49-32

5. If the obtained readings are substantially different from the specifications above, replace the sending unit.