I've been trying to locate this on an S4 N/A. A few threads were helpful but the only pictures I've found are for the S5. I've unplugged the temp sensor on the bottom of the radiator, the car still jumps to around 2500 RPM at startup. I'm not sure if this is normal due to the thermowax or if I still need to remove components of the AWS system.

Any help be appreciated!

 

there is an easy test to see if its the AWS or the thermowax.

start it up, when it goes to 2500rpm, put it in gear, if it comes down like someone flipped a switch (which is literally what happens), then its the AWS. if nothing happens, then its the thermowax.

alternatively, you can let it rev to 2500, and after 30 seconds it'll drop down the same way as if you put it in gear, it should drop to ~1800ish.

if you find it is the thermowax. step one is to pull the hose off and make sure its not clogged with crud. once you've cleaned out the hoses and bled the air out, the thermowax is fully adjustable both for the length of time its on, and how many rpms it does.

Foxed.ca - Mazda RX-7 Manuals <-- link to shop manuals