Small Victory
So, the primary cooling fan would not kick on. Even when the car was close to overheating. I tested 4 different coolant temperature sensors:
Bridged relays:
And verified wiring integrity to the PCM:
Everything checked out. Long story short, after many hours, I discovered it was the #1 relay wire (blue/yellow) for the fan connectors not making a connection:
I had actually forgotten to reconnect it for a few weeks after my reconditioning of the car a couple of months ago, and I guess some dirt/grime had found its way into the plug(s), so when I eventually reconnected it, the #1 relay wire at least (blue/yellow) didn’t make contact.
I spent the better part of yesterday afternoon confirming the wiring integrity from the coolant temp sensor to the PCM (all good). What tipped me off is when the car was idling in the driveway, and the thermostat read 212F via my IR thermometer, and the fan still wasn’t kicking on, I decided to swap out relays again. And I felt the primary relay click when I pushed it in. So it was clear the PCM was TRYING to turn the fan on.
Last night, I tested the integrity of the power wire from the #1 relay to the connector (good), and then bridged the relay. The fan didn’t initially turn on BUT I heard a small pop when I unplugged the connector with the relay still bridged. Got some contact cleaner and a brush, cleaned out the connector. Eased them back together, and the fan kicked on. Eureka.
It’ll be SO nice to not have to worry about the temp creeping up 95° stop-and-go traffic anymore.