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1973-74 Time Relay

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Remove temperature switch connector. Check relay to make sure that it is cool, then turn ignition on. Vacuum advance solenoid should energize for 20 seconds and then de-energize. If solenoid does not de-energize, remove blue lead from time relay. Solenoid will de-energize if relay is at fault.

Fig 1: 1970 TCS SYSTEM
G09325373Courtesy of GENERAL MOTORS COMPANY
Fig 2: 1972-74 TCS SYSTEM (ENGINE OFF)
G09325374Courtesy of GENERAL MOTORS COMPANY
Fig 3: 1972-74 TCS SYSTEM (LOW GEAR)
G09325375Courtesy of GENERAL MOTORS COMPANY
Fig 4: 1972-74 TCS SYSTEM (HIGH GEAR)
G09325376Courtesy of GENERAL MOTORS COMPANY
Fig 5: 1972-74 TCS SYSTEM (COLD TEMP. OVERRIDE ENERGIZED)
G09325377Courtesy of GENERAL MOTORS COMPANY