1977 Mazda Cosmo Automatic TransFACTORY OEM SERVICE PROCEDURE

Water Temperature Switch

Remove switch from water pump housing. Place switch in container of water and heat water slowly. With ohmmeter connected to switch terminals, check water temperature when continuity no longer exists in switch. Continuity should be broken when temperature reaches 129-151Β°F (54-66Β°C). Replace switch if it does not operate within specifications.

Fig 1: Coolant Temperature Gauges
G09309990Courtesy of MAZDA MOTORS CORP.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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