With voltmeter I tested red/yellow wire connector to the ECT switch but only got 5 volts – is this normal voltage for this wire; should it be like 12V? Where does this wire lead to? I'm assuming to the fuse box under hood. Too tight of a space to try to trace connector wires. Haynes book did not have cooling wiring diagram; just engine chassis stuff.

Without radiator fan I can still drive car without overheating -- coolant temperature gauge on dashboard needle is about halfway mark. No big deal.

Things i've done so far:
1. replaced radiator fan because it was leaking
2. check fuse – ok
3. check relay: swap fan relay with A/C fan relay and AC/fan still works
4. jump wires directly to radiator fan and it works
5. unplug ECT connector and used paper clip to connect both ends of pin, fan still does not work

Don't know where to go from here...

 

Wrong ECT sensor. The switch/sensor you need to test is located on the thermostat housing. It has Grn and Blk wires.

 

Thanks for the correction! I tested with both ends of pin to connector and fan turns on! I will replace this switch. Now i need to find huge socket to replace this part... thanks for your help...

 

Before replacing the switch, bleed the cooling system. Trapped air in the system can prevent the switch from working.

 

ok. i didn't know that. I'll bleed it entirely. Thanks.

 

After replacing the radiator fan switch, radiator fan is working again! Appreciate your help RonJ@HT!