Never run into this problem on our 89, but when the 87 signals refuse to blink, I tighten the alternator belt a little. Works every time.

Oh, and disassembly of that little switch is best done inside a sandwich bag. You won't lose the springs and balls when they go flying.

87 Montero, bought new, by me -
88/89 intercooled Starion Turbo engine-
with awesome audio.