[ferrari355]

Originally Posted by MNBoxster

Hi,

To check the Fans, turn on the AC - the Fans default to ON with the AC, this will tell you if the Fans do operate, but not necessesarily whether they are Temperature responsive.

As mentioned check the fuses (C8 - Rht., C10 - Lft.) but also check the relays. The Boxster uses two-stage (speed) Cooling Fans controlled by a resistor integral to the wiring harness. The fans have a Relay for each speed (Low/High). These are #19-22 (#19 - Lft. Low, #20 - Rht. Low, #21 - Lft. High, #22 - Rht. High) in the underdash Relay tray.

But, since you also report unusual Gauge Readings, I might also suspect the Coolant Temperature Sensor. This is because it is an NTC Resistor which sends a signal to the Temperature Gauge (pins 1,3) and to the DME which it uses to energize the Cooling Fans (pins 2,4). If you have a Code Reader, download any codes you may have stored (these will not all throw a CEL). In particular, look for codes P0115, P0117, P0118. If you have a faulty Thermostat, this can also throw a P0115 code as well. Hope this helps...

Happy Motoring!... Jim'99

well, today i opened the dust cover and used a battery connected to the fan directly and the fan worked. also i checked the relays, i did switch the #19 20 21 22 and still only the only right fan is working so i dont think is the reley. but when i check the fuse box i cant find where is the c8 and c10 because it only had numbers on it i cant find where is the "c" 10. so what i am thinking is the resistor for the fan, but where is that?