What are the two wires on the Cruze thermostat?
4 Answers
The two wires on the Cruze thermostat are a ground wire and a signal wire. The thermostat is a valve that controls the flow path of coolant, serving as an automatic temperature-regulating device. It typically contains a temperature-sensing component that opens or closes the flow of air, gas, or liquid through thermal expansion or contraction. The Chevrolet Cruze is a compact benchmark model designed by General Motors for both design and performance. The vehicle measures 4666mm in length, 1807mm in width, and 1460mm in height, with a wheelbase of 2700mm. The Cruze's dynamic coupe styling innovatively interprets the characteristics of traditional three-box sedans. Its classic front grille, sculpted shoulder lines, and dual-cockpit interior design showcase Chevrolet's new design language.
Hey, that time when my Cruze had the low coolant temperature warning light on, I went to fix the thermostat and found two wires on it, usually a red positive wire and a black ground wire. They are power wires supplying electricity to the internal heating element of the thermostat. When the vehicle is cold-started, the ECU controls the heating to quickly open the thermostat, allowing the coolant to circulate and helping the engine warm up faster to reduce emissions. If these two wires are broken or have poor contact, the coolant temperature may become abnormally high or low, and a P0128 fault code may appear on the dashboard. Later, I checked and found that the positive wire comes from the fuse box, and the ground wire is connected to the vehicle's frame. When repairing it yourself, remember to disconnect the battery to prevent short circuits and use a multimeter to check the voltage. Common issues include oxidation, corrosion, and aging of the connectors, which over time can cause problems affecting engine performance. Replacing the faulty parts promptly can solve the issue.
Regarding the two wires on the Cruze thermostat, those are actually electrical heating circuits—one is the positive power supply wire and the other is the ground return wire. The design is quite ingenious. During cold starts, the ECM sends a signal to allow current to pass through the heating element, warming the wax pellet to rapidly expand and open the valve, accelerating coolant flow to reduce cold-start emissions and fuel consumption. During normal use, if the wiring harness is damaged or the fuse blows, it can cause unstable coolant temperature, illuminate the engine light, and trigger a P0128 code. Checking it yourself is simple: first, turn off the power, unplug the connector, and use a test pen to check for continuity—normal voltage should be around 12V. Otherwise, replace the fuse or the entire thermostat assembly, and don’t forget to apply sealant to prevent leaks.
I've repaired similar cases where two wires are typically the power input for the thermostat heating. When the system detects a cold state, it energizes to heat up, opening the valve in advance to ensure rapid engine warm-up. If the wires are broken, the water temperature will be abnormal. Check the fuse and connectors.
