Fan, fuse and relay is good. I can inject 12 volts at relay and fan works. The sensor on engine resistance seems ok but voltage is not right. I hooked a 100 ohms resistor in hope that would trick ECU into turning on the fan relay with no luck.
I need to pull ECU and check wiring and contacts for corrosion. I have unhooked battery in hopes of resetting computer. Raining now.
If ECU is bad I may just install a toggle switch and run fan that way.
Now that cooler weather is here the fan will not be coming on much anyway. I hope there is not another problem lurking around.