Standard Ignition FLS309 Engine Coolant Level Sensor

Engine Coolant Level Sensor for OE Replacement

Standard Ignition FLS309 is a direct-fit engine coolant level sensor built for OE-style replacement on vehicles that use a 3-terminal blade connection. It is made for accurate electrical switching and dependable coolant level monitoring in applications such as Ford F-150 and Chevrolet Silverado service repairs.

With copper alloy conductors and 100% testing during production, FLS309 supports consistent conductivity and verified mechanical and electrical switching performance. The female connector and male blade terminals help match the original sensor interface for straightforward service work.

Key Features

• Direct-fit OE replacement for proper fit, form, and function
• Female connector with 1 connector interface
• 3 male blade terminals for the original electrical layout
• Copper alloy conductors for strong electrical conductivity and low resistive loss
• 100% tested for mechanical and electrical switching performance
• Standard Ignition FLS309 for coolant level sensor replacement

Detailed Product Information

This engine coolant level sensor is used to monitor coolant level in the reservoir or tank and send the signal needed by the vehicle’s warning system. Standard Ignition FLS309 is built as an OE replacement, making it a practical choice when servicing coolant level warning faults on Ford F-150, Chevrolet Silverado, and other light-duty truck applications that use this connector and terminal configuration. The part number FLS309 is also referenced by Dorman - HD Solutions 904-7631 and Four Seasons 37999 for the same application.

Common Problems It Can Help Solve

• Coolant level warning light staying on
• Intermittent low coolant alerts
• Faulty sensor signal from corrosion or internal wear
• Electrical connection issues at the coolant reservoir sensor
• Replacement needs after sensor failure during cooling system service

Installation Notes and Tips

Verify connector style, terminal count, and sensor location before installation. Confirm the vehicle uses a female connector with 3 male blade terminals, and inspect the harness and reservoir opening for damage or contamination before transferring the new sensor into service. For fitment-specific repairs, match the original sensor configuration on the vehicle, including Ford F-150 and Chevrolet Silverado applications where applicable.

Quality Assurance

Standard Ignition states that this sensor undergoes full testing to confirm mechanical and electrical switching performance. The brand also maintains quality control throughout manufacturing, from materials selection through final production, to support consistent replacement part performance.