The SPAL cooling fan switch features 3/8" NPT threads on a stainless steel, hermetically-sealed body. Thermal fan switch threads into your intake manifold or cylinder head and activates a relay (not included, sold seperately) when the bulb is immersed in coolant that is 185° F or 195° F, depending on which electric fan switch you use. As the engine cools, the contacts on the fan relay switch open, and the fan stops automatically.

Make sure the electric fan switch bulb is submerged in the HOT engine coolant.

Non-adjustable radiator fan sensor
Operating Switch Range: 35° F to 480° F
Max Current & Voltage: 3 amp, 32 VDC
Grounded case only

Specifications

KEY SPECS
MFG. Part #	Select Temperature to see
Brand	SPAL
Temp. Range	Select Temperature to see
Thread Pitch	3/8" NPT
Material Type	Steel

GENERAL
Sold in Quantity	Each
GTIN Code	Select Temperature to see
Overall Height	2.25"
Operating Temperature	185 °F

Ratings & Reviews

4.5

39 Reviews

Overall Assessment

Customers appreciate the efficiency and reliability of our product, which consistently controls the operation of a radiator cooler fan to maintain optimal engine temperature. Many find it easy to install and accurately responsive to changing temperatures. It has proven especially useful for classic car models and electric fans. Some customers, however, noted size limitations of the bulb sensing end and discrepancies in switch temps. The need for occasional replacements was reported, suggesting durability could be enhanced. Nonetheless, satisfaction rates are high, with many users eager to recommend the product, emphasizing its practicality and effectiveness.

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4.5

39 reviews

Most Liked Positive Review

5.0

I would buy this product agian and agian! Its great.

I installed it in my water pump and it works great just like described. I would reccomend running a toggle switch to manually override the fans to turn on so you can run the fans if your engine over-heats so it can still cool without the engine running. Very efficent and useful!

Most Liked Negative Review

3.0

Instructions needs sealant ID

SPAL needs to step up and identify a sealant that will seal and still provide continuity. They caution about Teflon tape but give you nothing else. I installed with no sealant and had leaks almost stripped it out before removing and putting a sealant on the threads.

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Yes

5.0

9 months ago

Hammond, La

Verified

Perfect fit

Would Recommend

I would ensure that you have an accurate water temp gauge.

5.0

3 years ago

Carl

Verified

Bought one 185 on/165 off switch and installed. Turned on fans at 195 and off at 175. Called and was sent second switch. This one turns on fans at 195 and within 15 seconds turns off fans at 190. A pain to change since radiator has to be drained some before changeout. And have to wait for system to cool down.

Only need one

4.0

4 years ago

None

Kingsland, GA

Verified

Will control the operation of a radiator cooler fan.

Would Recommend

Yes

5.0

5 years ago

Josh

Salisbury ma

Verified

I was very satisfied with the piece it worked great

Would Recommend

excellent build

4.0

5 years ago

Doug

Huntsville

Verified

luv spedway

I would buy again

5.0

5 years ago

Tracey

Liberty mo.

Verified

Used on 1969 396,worked great.

Would Recommend

Size is big!

4.0

6 years ago

Paul

Verified

Bulb sensing end could be smaller! Doesn't fit in adapter!

Worked great

5.0

6 years ago

Ranman

Tennessee

Verified

Turns fan on at 205 and off at 195.

Would Recommend

Hot stuff to keep your cool

5.0

7 years ago

Buck

Bradenton, FL

Verified

Works like a charm. The old replaced unit wasn't turning on the radiator fan on early enough and the engine was not running at its optimum temperature. This item fixed the problem.

Would Recommend

Worked perfectly...

5.0

7 years ago

Eric

Mesa AZ

Verified

Installed on 74 Nova with 350 small block to operate electric fans with block/head temp rather than radiator thermometer. Worked perfectly after reaching engine operating temp, fans came on as desired and stop when cooling range was reached.

Would Recommend

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Showing 10 of 39 reviews

Questions & Answers

9 Questions • 9 Answers

Sort Questions

I have a spal cooling fan sensor that is a temp range 185 on 165 off . I have an autometer temp gauge and going by the temp gauge its turning the fan on at 200 and shutting fan off at 185 . just wondering what could be causing it to be off by so much ?

by Josh

• 8 years ago

1 answer

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how do you wire it with a relay?

by bill

• 9 years ago

1 answer

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Was wondering what degree of thermostat to run with the fan theramal switch that turns on around 195 if I put sensor in an alum SBC head?

by Red

• 9 years ago

1 answer

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I purchased this thinking I needed a 3/8 NPT but I really needed a 1/2 NPT, so I tried a typical black pipe 3/8 to 1/2 NPT adapter but the Spal sensor would not fit all the way through -- the through bore ID below the threads was a smaller diamter than the OD of the sensor. Will your adapters work? Will you verify for me?

by Thrownrod

• 9 years ago

1 answer

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Will a quick spike of temp over the turn on temp cause the fan to come on, or does it take a consistent turn on temp for a certain amount of time to turn fan on. I currently have a 185 degree on and 165 degree of sensor installed and have seen where my temp by gage will spike to 210 degrees without the fan turning on.

by Mike

• 11 years ago

1 answer

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Operating Range? What is the Operating Range of this Temp Switch? At what Temperature does the Switch Close and at what Temperature does the Switch Open?

by DedicateDF100

• 11 years ago

1 answer

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is this a thermistor type sensor that sends a resistance signal to the control box

by nicklut

• 11 years ago

1 answer

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Is this a fail safe switch were the fan will run continously if the switch fails.

by Louis

• 15 years ago

1 answer

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Hello, where is the best place for fix it on a 350 chevy with aluminium heads on my rod I fixed on the right passenger side at the rear of engine just behind the exhaust pipes.And now when I read on my dolphin gauge it start the fan at 210° what do you th

• 15 years ago

1 answer

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9 of 9 questions shown