1991 Nissan-Datsun Sentra SE-RFACTORY OEM SERVICE PROCEDURE

Radiator (Cooling) Fan Control Relay(S)

See RELAYSΒ  under RELAYS & SOLENOIDS. Also see appropriate table under RADIATOR COOLING FAN CONTROL RELAY OPERATION for relay(s) operation.

A/C SWITCH ON

Engine Coolant Temp.Β°F (Β°C) Vehicle Speed MPH Radiator Fan
Less Than 202 (94) 50 Or More Off
" 49 Or Less Low
203-210 (95-99) N/A Low
Greater Than 212 (100) N/A (1) Low; (2) High
(1) Vehicles equipped with manual transmission.
(2) Vehicles equipped with automatic transmission
A/C SWITCH OFF

Engine Coolant Temp.Β°F (Β°C) Vehicle Speed MPH Radiator Fans
Less Than 195 (90) N/A Off
196-201 (91-94) 12 Or More Off
" 12 Or Less Low
203-210 (95-99) 50 Or More Off
" 49 Or Less Low
Greater Than 212 (100) N/A (1) Low; (2) High
(1) Vehicles equipped with manual transmission.
(2) Vehicles equipped with automatic transmission
Fig 1: Identifying Diagnostic Chart Symbols
G90A20594Courtesy of NISSAN MOTOR CO., U.S.A.
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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