Standard Ignition TS-158 Engine Cooling Fan Switch

Engine Cooling Fan Switch for Ford Tempo and Mercury Topaz

Standard Ignition TS-158 is an engine cooling fan switch built for precise fan control in select Ford Tempo and Mercury Topaz applications. It uses a factory-calibrated thermal design with a formed bimetal contact arm to trigger electrical contact at the specified temperature.

• Engine cooling fan switch for thermal fan control
• Factory-calibrated actuation point for consistent operation
• Formed bimetallic contact arm for precise electrical switching
• Female connector with 2 blade terminals
• Gold and gray finish with dichromate and plastic construction

Detailed Product Overview

Standard Ignition TS-158 is engineered with custom wax and bimetal-based thermal switching technology to transfer the electrical signal to the fan controller when the set temperature is reached. Each unit is calibrated and tested during production to confirm switch actuation at the specified lower-temperature set point. This part cross-references Airtex Fuel Pumps FS103 for the same application. Fits 1984-1994 Ford Tempo and Fits 1984-1994 Mercury Topaz, N/A. The TS-158 is a direct-fit cooling fan switch choice for drivers servicing temperature control circuits on these vehicles.

Common Issues This Part Can Address

• Cooling fan not switching on at the proper temperature
• Fan cycling inconsistently during engine warm-up
• Overheating caused by delayed fan activation
• Fault codes or drivability concerns tied to fan control circuit failure
• Worn or inaccurate thermal switch response

Installation Notes and Tips

Verify connector style, terminal count, and mounting location before installation. The TS-158 uses a female connector and 2 blade terminals, so the harness should match the original configuration. Confirm the replacement switch matches the vehicle’s specified temperature range and inspect the cooling fan circuit for corrosion or damaged wiring during service.

Quality Assurance

Standard Ignition manufactures this switch with complete process control from component selection through final testing. Each thermal switch is calibrated to meet its specified actuation temperature, supporting consistent performance in service.