So i have a 82gsl with a 12a and s4 wp housing and s4 fuse block. I would like to know what thermoswitch i should use as my fan is always on. Is pn41-18-840 a option and how would i hook it up?

 

I ended up pushing a thinly threaded (like 1/8in diameter) probe in between the radiator fins and ran a switch inside the car just in case it didn't work. Held in with a zip tie or two, not the best way but it worked in a turbo swapped car.

 

Search "adjustable fan controller" at Autozone.com The one I use cost under 20 bucks and works great...



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the p/n is 733653 at autozone or p/n 226203 at advance auto. where do you put the probe? it doesnt look like it would go in the fins?

 

You push the probe through the radiator fins near the upper hose inlet. It's a little nerve racking but just be careful and you won't damage the radiator

 

I was thinking one that threads into thermostat outlet. I was checking the napa sight and found some but idk if thell fit they all have 3/8 threads?

 

I zip tied the probe to the back of the radiator, right under the inlet pipe (hottest point)...

 

Re-tap the housing. I did and it's been fine; no leaks.

 

I really like your solution jr515. Only thing with this, for me anyway is that I prefer to get my signal from the water pump housing, pre thermostat, I have found that doing it this way turns the fan on a bit earlier and helped maintain a cooler average temp.

 

Good point Army of One. I didn't want drill/tap the wp housing. The only port I have is being used for my aftermarket temp gauge.

 

Stock S4NA thermoswitch port is M16x1.5 thread. A lot of Japanese cars use this size, including a bunch of Hondas from the 80s. Since the S5 thermoswitch's connector is difficult to find, a suitable alternative is the 1974 Subaru GL thermoswitch. Same M16x1.5 threads as stock, turns on at 203 degrees, comparable to the S5 switch (207 degrees), but uses a common bullet connector. The wrench hex is a bit bigger, but it fits and works like a S5T2 fan thermoswitch for 1/5 the price.

 

You should run the thermal probe near the bottom where the engine return line is.
With the probe high in the radiator you risk over heating. First it will turn on every time the thermostat opens but won't be able to measure how much the coolant has been cooled b4 it goes into the block.

If you are low on coolant it will not run long enough and overheat your motor.

Use the probe type and put it in near the return at the bottom of the radiator.

 

I was able to get a s5 switch from a shop for 5 bux. Also a co worker showed me how it works since its two prong i didnt know one goes to relay other goes to ground. So ill try it and let you know if it works

 

I use one of these inline in the radiator hose with a sensor.
radiator hose adapter | eBay

 

If you want I have a nice digital unit that uses a radiator probe. I'll sell it to you. It's fully adjustable, shows live temp and is brand new. Comes with fan fuse and 40amp relay. $55.

 

Thanks but i just got the s5 one to work