Sending Unit Check
- Connect voltmeter to Yellow/White wire connector of coolant temperature gauge sending unit. Sending unit is located on intake manifold. Turn ignition on. Ensure Yellow/White wire is supplied with 2-7 volts from gauge. If not, repair wiring circuit. See appropriate chassis wiring diagram in the WIRING DIAGRAMS
section.
- If voltage supply to sending unit is good. Remove sending unit from engine. Measure sending unit resistance in heated water. See Fig 1
. Resistance should decrease as water temperature increases. See COOLANT TEMPERATURE SENDING UNIT RESISTANCE table. If resistance does not vary as indicated, replace sender.
Courtesy of GENERAL MOTORS CORP. COOLANT TEMPERATURE SENDING UNIT RESISTANCE
| Model |
Temperature °F (°C) |
Ohms |
| Metro & Tracker |
122 (50) |
133 |
| " |
176 (80) |
47.5 -56.8 |
| " |
212 (100) |
26.2 -29.3 |
| Prizm |
122 (50) |
190-260 |
| " |
140 (60) |
152-154 |
| " |
239 (115) |
24-28 |
| " |
239 (115) |
23-28 |
| Storm |
122 (50) |
226 |
| " |
293 (115) |
26.4 |