84-86 headlight motors are well known for that. It sounds like you're hearing the relays/motors click until the thermal breaker in the motors trips. The silence you hear is the time it takes for the breaker to cool off and reset itself.
I always recomend that people upgrade to the Gen 2 motors rather than waste time and moeny on the lame first gen system. Even if you rebuild the whole system... It is real common that no sooner do people get the old system working then something else breaks in it. The Gen 2 system is faster tougher and way more reliable.
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