Second temperature sensor location

[Clod_King]

I have a purchased a dual radiator fan controller for my car and I am looking for a location to install a second temperature sensor. The manual for the fan controller says to find a location in the head, but I do not see one. Maybe I am blind or just a dumb-dumb, but it seems that there is only the one location in the thermostat housing. Has anyone installed a second sensor somewhere that isn't the one that comes stock in the radiator on A/C equipped cars? My car does not have A/C and therefore I do not have an extra bung waiting to be filled. Alos I do not want to read the temperature of the coolant within the radiator, that seems kind of silly. I would rather monitor the temperature of the hot coolant within the motor or near the output to the radiator.

Which leads me to another question I have been pondering. Which is the output for the coolant from the motor to the radiator? Is it the upper hose with the thermostat, or the lower hose? If it is the upper hose with that leaves the thermostat housing I can easily put the temperature sensor there since I have the version with the plug on the top. but I don't want to put it there if that is the cold side and would have to figure out somewhere else to put it. I guess buying a short aluminum tube of the proper diameter and welding in a bung then splicing it into the proper hose would be good, but I still need to know for sure which of the two larger hoses is the return for the radiator. Conventional wisdom would dictate that you would want the hot coolant to run past the thermostat to properly operate it, but again as I said I could be a dumb-dumb. Maybe I could try running the motor with two half filled buckets and try to pump the water from one bucket into the other bucket and that would prove which hose does what, but I would rather not do that if somebody has the for sure answer.

Thanks in advance.

[andyf]

No you`re right, top hose is the hot one to the rad. You can get a pre-made aluminium sender holder to fit into the top hose where you can screw the sender into. Just cut the hose on a straight part, removing a bit and fit in place, easy peasy. I have one for the operation of my electric cooling fan.

All you need is the top hose internal diameter to order the correct size (and a couple of hose clips).

[Clod_King]

Excellent. Thank you Andy! I'm gonna just pop the plug out of the thermostat housing/upper hose nipple housing and pop that sensor in there. I'm glad someone had a quick response on here for me.

[UKPhilTR7]

I agree with Andy, as that is where I have my sensor running from too. I got the hose fitting of the net and connected it all in. Cutting the top hose is easier than fabricating a new housing for a new sensor. Also if you have the controller unit in the corner by your front headlight wires, the cable for the sensor can trail nicely along the hose and then rad to the controller unit.

[Clod_King]

I'll look into that for sure. But I may take off one of the intakes and drill and tap for a second sensor location. One is definitely easier than the other but I like the idea of having the sensor on the motor for aesthetic purposes. But yeah slicing the hose and fitting a tube would be much much easier.