Some 1970 vehicles built after June 30 are equipped with the 1971 design turn signal switch. The 1971 switch is different from 1970 in the following ways:
• The emergency flashers work when the switch button is pulled out.
• There is no automatic cancel for the emergency flasher switch.
• The wire color code is slightly different as indicated in the chart below.
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PRODUCTION CORRECTION: June 30, 1970.
WARRANTY STATUS: INFORMATION ONLY
Reference from http://www.fordification.com/tsb/viewto ... ?f=5&t=674