T100 Regular Cab Pickup 2WD L4-2693cc 2.7L DOHC MFI (1998)
Turn Signal Flasher: Testing and Inspection
INSPECT TURN SIGNAL FLASHER OPERATION
a. Connect the positive (+) lead from the battery to terminal 3 and the negative (-) lead to terminal 1.
b. Connect the 2 turn signal light bulbs in parallel to each other to terminals 1 and 2, check that the bulbs flash.
HINT: The turn signal lights should flash 60 to 120 times par minute.
If one of the front or rear turn signal lights has an open circuit, the number of flashes will be more than 140 per minute.
If operation is not as specified, replace the flasher.