I just finished putting in my JDM ITR swap into my 99 GSR.

However, Im running into a little problem. I Turn on the car and let it warm up but the fan never turns on. the fan is hooked up and all.

i took it around the block to see waht it does. temp stayed normal but steam started coming out of the hood. steam was forcing its way from under the cap.

could it be the thermostat? i have a mugen thermostat and fan switch.

 

anybody?

 

sounds like you have an air lock.. Not sure if your motor is same as the GSR but i was having same problem so i took hose off of head spout. The little hose that goes to the throttle body that is. Then I filled it up with antifreeze through the normal rad cap until it started to come out of the hose that goes to the throttlebody. Worked awesome. Took it around block and then topped it up.