the large relay closest to wiper motor is the fan delay , at low voltage it will active , as you saw when you touched the battery wire , but it will also fail and turn fans on when you least expect
if you run a 160 therm you dont need the relay as it should never see temps needed to make it activate (which it only does with key off) and then its supposed to only run for a couple minutes
just unplug the two connectors and leave them off . youll never miss it and you can be sure it will never fail
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