The Stovebolt Site Forums The Shop Area Engine Shop Electric fan switch

Does anyone know of a fan control thermo switch that has pipe threads for installation in an intake manifold and a turn on temperature of about 200*F and a turn off temperature of about 190*F? Speedway Motors has one that is close with a turn off temperature of 185*F but that does not seem like a good choice when using a 180* thermostat because there is not enough difference between the thermostat and turn off temperature.

Wells and BWD make switches in the range I'm looking for but they have metric threads, typically M16 x 1.5. My old lathe cuts inch threads but not metric threads.

Thanks!

When I have a question that involves auto electrical I call Mad Electrical.
http://www.madelectrical.com/index.shtml
He will talk all day but might cover your question.

Consider that where you install it (back of head?) might not be same temp as the thermostat.
I don't see the 5* difference as a problem?

All sorts of good quality switches and controllers here
http://www.spalusa.com/store/main.aspx?p=CategoryBody&c=FAAC

The "Automatic Programmable Fan Controller" from SPAL is what I'm expecting to use in my truck.

Grigg

Big Chev 3600, thank you very much for the response. I think I should have been more specific in my question. I'm looking for a thermo switch that is a common auto parts store item that is either in stock or available by special order so it can be easily replaced in the future if necessary.

There is actually a male 1/2" NPT to female M16 x 1.5 adaptor that I found on, of all places a beer home brewing forum. That would be an option for me if I can't find a pipe thread thermo switch and have to use one with metric threads.

To me the quest for stuff like this is part of the fun of the car hobby.

Ray

check out your local speed shop.I have a dial in temp switch on my electric fan. the temp prob screws into the rad drain pet cock.you may want to set the temp at 180 for the fan to kick on.you don't want the catch up game in traffic.Only elec fan for cooling.also have a cooling fan on trans fluid line.700r4

Dan-pa, this is a street rod with a 350 small block Chevy engine and a 2004R trans. The trans is cooled by a cooler from Bow Tie Overdrives mounted in front of the radiator. The radiator is an aluminum unit from Speedway Motors and it keeps the trans temperature below 140* even on 100* days.

There is a 180* thermostat in the engine, so with a fan switch that switches on at 180* once it comes on it would run continuously. Right now it has a thermo switch and relay from Painless and it switches on at about 195* and off at about 185*. Because the thermostat and switch off temperatures are essentailly the same, given the slight inaccuracies of those devices, the fan sometimes never goes off once it comes on even though the temperature is at the 180* maintained by the thermostat.

That is why I'm looking for a switch off temp of about 190* to create a gap between the thermostat minimum temp and the switch off temp. There will probably be a little bit of trial and error in this.

What kind of switch did you find to install in the radiator lower tank? That is intersting because that is probably the coolest place in the cooling system. I actually thought of relocating my thermo switch from the intake manifold near the thermostat (a hot spot) to the water pump (a cooler spot).

Thank you for the suggestion.

The one in my '56 has adjustable on but not off. Mine works off the electric temp gauge.

Yar.looked up address for therm switch.Now I brought this switch over 10 yrs ago.The address is: Ron Frances Wire Works.com Phone # 800-292-1940. 200 keystone road, Chester,Pa.19013 They will answer any ??? you may have.

"The trans is cooled by a cooler from Bow Tie Overdrives mounted in front of the radiator. The radiator is an aluminum unit from Speedway Motors and it keeps the trans temperature below 140* even on 100* days."

Oops, I had a senior moment in stating the above.

What I MEANT was the trans cooler keeps the trans fluid temperature below 140 and the Speedway radiator maintains an engine coolant temperature between the thermostat opening temperature of 180* and a maximum of about 195*, even on uphill pulls on hot days.

Thanks for that extra info dan-pa

I used an adjustable temp. sensor from Flexalite. Has a probe which inserts thru radiator fins, and adjustable switch you can set from 180* to 240*