Gauge Readings Are Inaccurate
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1991 GMC Pickup, 1991 GMC Cab & Chassis, 1991 GMC C3500 HD, 1991 Chevrolet Pickup, and 1991 Chevrolet Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
- Check wiring for corroded or loose connections. Clean and tighten terminals and connections as necessary. Also check resistance in temperature sending unit ground circuit. If terminals, connections and ground circuit are okay, go to next step.
- Disconnect lead connector from temperature gauge sending unit. Using an ohmmeter, test sending unit resistance. See TEMPERATURE GAUGE SENDING UNIT RESISTANCE table. If sending unit values are incorrect, replace temperature gauge sending unit.
TEMPERATURE GAUGE SENDING UNIT RESISTANCE
| Degrees °F (°C) | Ohms |
|---|---|
| 104 (40) | 1365 |
| 257 (125) | 55 |