Need help! Gas engine overheating. Cannot resolve.

30 AMP RDI & CDS fuses you mentioned are in blue circle in the image. Just remove it, and visually check it + use multimeter to test continuity? I had previously checked each and every fuse except for these three since these are joined together. Thanks again @rjparker !

 

I just checked all three fuses ( 2 30A, and 1 10A), and all three checked out. There is continuity. Next I will check fan wiring connectors soon as I figure out how to reach and disconnect these.

 

Techstream is not free but is the Toyota scanner known to be complete. Others in the $500 up range may work as well. In this particular case just operating the ac is enough.

Electrical diagnostics can be tricky from a base understanding level and from accessibility.

Continuity is not checking the circuit. You have to measure voltages. While not likely, both fans could be bad or they could be running but might be hard to hear with the engine rattling.

A one minute test is to open the hood and have a strong light to see the fan blades. Ready the car with the headlights off but use the ev button to keep the engine from running.

In Ready have someone turn the ac on and within a couple of seconds the fans should come on audibly and visually. Turn the ac off and they should shutdown.

The radiator fan power for one fan is accessible between the inverter and fan assembly on the driver's side. It should be possible to back probe that connector in place. I would set the meter for dc volts (in a range to measure 12-15 vdc) and use very fine probe tips, ideally needle probes.

 

One tool a good auto mechanic has are relay test jumpers (relay socket breakout adapters).

• Relay test jumpers are essentially adapters that plug into a relay's socket with the relay plugged in on top of it, providing access to the terminals and circuit wiring through adapter test points.
• These test points allow for easy connection of meter probes, test leads, or an amp clamp for diagnostic testing.
• They come in various kits, often including different relay sizes and types to fit various relay models.

The most common are from Lisle with a set like their Lisle 60660.

60660 Deluxe Relay Test Set | Lisle Corporation

The bottom line is a good shop can make short work of this kind of diagnosis.