So the PCM isn't grounding at pin 31 to turn on the high speed relay? That system is sort of common. The fan is a 2 speed unit. Apply 12 volts to the Yellow lead and it runs on low, remove that and apply 12 volts to the Light green/ yellow stripe and it should spin up on high. The PCM should show a ground at pin 35 and pin 31 when the coolant temp hits 230 F
That turns on both relays, the low speed switches to an open circuit while the high speed relay switches power to the other terminal of the fan for high speed.
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Sunday, June 2nd, 2019 AT 6:17 PM