Does anyone have any schematics/diagrams relating how the cooling fan speed is controlled (1993 sc400 btw)?

 

What do you need to know?

Here's the wiring diagram.....

KC

 

That's awesome! Thanks. I was trying to figure out exactly where the cooling ecu gets its temperature input for fan speed. From what I read on a particular 1UZ document I was lead to believe (albeit skeptically) that it might not be from the ecu's coolant temp sensor. Obviously it is from your diagram, and my coolant temp will start to rise at long stops because I used the factory coolant sensor for my standalone ecu and my fan speed doesn't kick up.

 

There are 3 coolant sensors on mine. The 1 in the radiator normally controls the cooling fans. 1 of the ones on the engine is for the ECU the other is for the gauge in the dash.

Hey, did you get your LC-1 situation sorted out yet? I sent mine back 2 weeks ago and haven't heard a thing from them. They have not responded to my email. Getting kind of worried.

KC

 

Here - shows where the sensor is......

KC

 

I had no idea about the radiator mounted sensor. Looks like google can't do it all for me. I figured out that the wideband works, but I could not get it to jive with tunerstudio for some reason. So, I just logged through the Innovate software which kind of sucked but whatever.

 

Definitely bumping this from the long dead but the diagrams are helpful and I wanted to thank the poster. Also does the kick up solenoid operate normally closed or open? If I unplug it and put 12v to it the fan will kick up full speed. I was under the impression if voltage was lost to the solenoid it would run full speed as a fail safe. Also does the AC switch hold priority over the coolant temp sensor?