While checking fluids on the wife's 01 RX 300, I noticed the fans never came on EXCEPT when she turned the a/c on. As soon as she turned it off, the fans went off. It never overheated. It's 83 degrees here today and I sure would have thought the fans should have kicked on in the 20 mins I had her run it. Any thoughts?

Thx
David

 

The fans rarely go on in my RX300, except of course when running the A/C. It's never overheated. They go on when stuck in traffic, in extreme heat (+100 degrees F).

The fans are actually quite quiet, which I like. Some cars really roar when the fans are on, these fans are relatively quiet.

 

RX engines run hotter than other vehicles I have owned.

Salim

 

It simply shows how efficient aluminum radiators are at dispelling the heat from the cooling system, especially with the engune running at idle and under no load. Under those conditions the combustion process is producing the least heat of any time it is running. Aluminum is an outstanding conductor of heat and the way aluminum radiators are constructed as apposed to copper radiators (strong emphasis on tight solder bond with aluminum as apposed to copper and HIGH fin count that is the KEY to carrying the heat away from the coolant) are the rerasons the fan doesn't run like you think it should. Put a conventional copper radiator, built the way they used to build them, in the RX and I can almost guarantee you the fan would be running intermittently to keep the coolant below the target fan temperature.
The fans are wired to AUTOMATICALLY run whenever the A/C position is selected.

 

Ty 58(and others) for the reply. That's good to know about the a/c. I didn't know if some yahoo wired the fans to the a/c or if that was factory.