Electric Fan Temp Sensor Placement

[MercuryMarc]

I have an adjustable temp switch that activates my electric radiator fan. I have the switch set at the lowest point which the manufacturer says is 150 degrees. But the switch turns on when my temp sensor in the block reads 210 degrees. I have the temp sensor switch probe placed between the rad fins next to the upper coolant intake hose, and I have also tried placing it lying on top of the radiator tank secured with a fitted piece of sheet metal. I can't get the darn thing to turn on at a lower temp.

Is there a hotter place I can attach the probe (like on the block)? I wonder if the Aluminum radiator doesn't conduct heat as well as the block and that is why the temp sensor turns on so late. By the way, this probe is the kind that cannot get wet and is externally mounted - it is from Derale.

Thanks-
Marc in SF
63 Comet with a 69 Falcon 200 ci Six, Aluminum Racing Radiator, 14 Inch Pusher Electric Fan, Tefba Filter, and extrenal Tranny Cooler
http://mercurycomet.net

 

[Guest]

You want the temp sender in the block reading the coolant temp direct.

Al

 

[Anonymous]

Can't you replace it with the wet type sensor and install it where the plug is in the gooseneck, and then the fan will come on when the thermostat opens.

 

[LaGrasta]

I have a 16" electric fan that probably going to be too big to use. I have to somhow combine it with my a/c condensor. I expect you discarded the mechanical fan in place of the new electric? How big is it? How is it mounted?

 

[MercuryMarc]

Thanks - looks like I need to get a sensor that is submerged in the coolant. Concerning the fan placement, I picked mine based on the maximum depth (width?) that I could fit between the radiator and the vertical hood latch brace. I found that most fans are 2.25 - 3.5 inches deep and that is a bigger limiting issue than the fan diameter. I actually picked up a spare vertical hood latch brace and cut out 1 inch to allow for a fatter fan. Yes - I removed the mechanical fan and the new (oversized) aluminum radiator sits closer to the water pump pulley. The fan is mounted by bolting the top horizontal section to the radiator support, and the bottom is secured by a fabricated sheet metal brace attached to verctical hood latch brace. Let me know if you need pics.

Marc in SF
63 Comet, 200 ci inline 6, Alum Rad, 14 inch Fan, Tefba Filter, Tranny Cooler
http://mercurycomet.net

 

[LaGrasta]

thanks for the info. It sounds like i have some fabbing to do.

 

[69.5Mav]

MercuryMarc
I went to the bone yard and got a sentra fan and temp switch for my 170ci mav. I monted the sentra temp switch in a threaded hole on a grey PVC elbow and inserted it in the upper radiator hose. If you want a higher coolant temperature you can insert the elbow into the lower radiator hose. The elbow gives enough meat to effectively put in threads. the fan is reversable depending on the polarity of the wireing to its terminals, so it can be mounted either in front of the radiator and push air throug or behind the radiator and pull air through. This setup was dirt cheap. I wired the fan so it would stay on even after the car was shut off to prevet any build up of heat, a dash mounted solar battery charger is used to keep the battery charged up.
69.5mav