Thermosensor (Fan Switch) Mod

[Marck]

I found a thermosensor that will kick the secondary fan on sooner than the factory one.

 

The operating range, according to my FSM, of the factory thermoswitch is 199F-207F. I am guessing it turns the fan on at around 207F and shuts it off at 199F. Way too hot for a suby, especially a turbo suby. You may crack a head if you risk letting the temperature raise past 3/4 of the guage.

 

I have searched through catalogs at Napa, Carquest, and Kragen looking for a thermosensor that will turn the secondary electric radiator fan at 180F and will screw into the stock location in the radiator. The one I found and used turns the radiator fan on at 185F and I think shuts it off at 176F, a good temp range for the turbo cars that are running the 180F or less thermostats. The fan will kick on when the needle is slightly higher than midway on the guage.

 

The thermosensor from Kragen is made by Niehoff and goes for under $30. The part number is TS81781 and can be found here online: http://www.partsamerica.com/ProductDetail.aspx?mfrcode=NIE&mfrpartnumber=TS81781

 

It is made for an 87-89 mitsubishi and 86-89 Hyundai. It of course has the same thread size which is M16 x 1.5. Click on the link and look at the picture of the sensor. The only modification you have to make is to cut the plug off of the wires coming out of the sensor and then crimp on a male spade onto each wire. Then plug the wires into the factory plug. No modification of the factory wiring is necessary.

 

This modification is a must for anyone who is trying to run their subarus with only the stock electric fan (ie. mechanical clutch fan removed). My plan is to use the new thermoswitch to trigger two relays which will each turn on an electric fan automatically. I will still have a toggle switch in the cabin incase anything goes wrong where I would need to manually turn on the fans.

 

Nice simple mod. Lets put this into the USRM.

[Prospeeder]

hmmm i may do this, can you just take the clutch fan out and put the little nuts on the pully to hold it on, wont cause any problems, hmmm, i might take it out then and put my elecctric fan in and use that thermosensor.