Where is the sensor that activates the electric fan? My fan doesnt seem to be turning on at the proper time or at all sometimes. I think its somewhere near the thermostat housing but i dont know. And if someone could tell me if it is safe to remove my thermostat because i think there may be some sealant clogging it, so would it just be okay to run the car without it? thanks for the help.

 

its ok to remove the thermostat but your car will take forever on cold mornings to warm up. also the hose coming from the bottom of the radiator likes to cinch itself closed when there is no thermostat causing overheating. Its best to just get a new one or clean out the one you have. the fan is activated by the coolant temp sensor next to the thermostat housing and intke plenum. it is a small plug that with wires that can easily be cleaned or plugged in firmly to be fixed instead of getting a new one.

 

not exactly correct... On single cam cars, the auxilary electric fan is activated by a thermostatic switch in the lower radiator hose. On dual cam cars, the aux electric fan is triggered by the ECU based on the AC system. I don't think the ECU can operate the fan based on temp. If it did, it could be exploited to control larger electric fans, and several reputable ECU hackers/tuners say that it cannot be done. Both cars do have two coolant temp sensors next to the thermostat housing. One operates the cluster gauge, and the other informs the ECU so that it can do cold idle and overheat retarding. The stock auxilary fan does not move very much air anyways.

 

cinch itself? dont want to assume anything. thanks for the help guys. by the way i have a DOHC if that means anything with the fan.

 

sohc s13 has a emergency 190 degree kick on switch for the front condensor fan in the lower hosed.. after 1991 most nissans went to ecu controlled condensor / overheat fans.. in both the sohc and dohc the condensor fan turns on with ac. On dohc when the computer sees anything over 188 it kicks the condesor fan on as a aux as well.. but this is ecu controlled... it is something that is hard wired and not reprogramable. This is true for almost any nissan past 1991... Wanna see ? Go take the plug off of the 2 wire temp sensor.. If your fan / wiring is working like stock.. then the ecu should kick the aux fan on as a safety precaution.

martin
xat

 

Ahh, since Martin is chiming in now, here's an idea.... Old Altimas with the KA24DE have fans that are controlled by the ECU directly because they have no fan clutch. I would bet that it's possible to run an S13 on an Altima ECU, then wire up the Altima electric fans (or other fans)....