Four Seasons 37900 Engine Coolant Temperature Sensor

Coolant Temp Sensor for Isuzu

Four Seasons 37900 is a coolant temperature sensor built for engine cooling system monitoring on select Isuzu applications. It uses a wire lead connector, a single terminal, and a 3/8" pipe thread size to match the specified OE-style fitment.

Compatible with 1983-1986 Isuzu Pickup and 1983-1984 Isuzu I-Mark, this Four Seasons coolant temp sensor is a direct-fit replacement for vehicles that use the listed thread and terminal configuration. The 37900 part number is also referenced for several OE and aftermarket interchange numbers.

Key Features

• Brand: Four Seasons Coolant Temp Sensor
• Part number: 37900
• Connector gender: wire lead
• Number of terminals: 1
• Fitting thread size: 3/8" Pipe (43/64" x 18)
• Meets or exceeds OEM requirements: YES
• Fits 1983-1986 Isuzu Pickup and 1983-1984 Isuzu I-Mark

Product Details

The Four Seasons Coolant Temp Sensor line focuses on temperature-sensing components used in engine cooling and fuel-management related circuits. This 37900 sensor is specified with a single-terminal, wire-lead design and a threaded pipe fitting, making it important to verify the thread size and connector style against the original part before installation. This part cross-references A14250 and MT1808 for the same application.

For Isuzu Pickup and Isuzu I-Mark service work, the 37900 coolant temp sensor supports accurate engine temperature signal input where the original sensor uses the same mounting and electrical configuration. It is listed as meeting or exceeding OEM requirements.

Common Issues This Part May Address

• Incorrect coolant temperature signal to the engine control system
• Hard starting or poor cold-engine operation related to temperature input
• Temperature gauge or warning light irregularities tied to the sensor circuit
• Rough idle or drivability concerns caused by inaccurate coolant temperature data
• Replacement of a damaged or corroded threaded sensor connection

Installation Notes and Tips

Confirm the vehicle uses a 3/8" pipe thread sensor with a single terminal and wire-lead connection before installation. Inspect the connector, harness condition, and sealing surface during service, and compare the removed sensor to the new Four Seasons 37900 unit to verify thread and terminal match. For best results, install on the listed Isuzu Pickup and Isuzu I-Mark applications only when the original configuration matches the part specifications.

Quality Assurance

Four Seasons lists this coolant temp sensor as meeting or exceeding OEM requirements. The 37900 part number is supported by multiple interchange references, which helps confirm application matching for the specified Isuzu vehicles.