Hey all!
just looking at different ways of wiring my electric fan setup that came with my afco radiator. I like the idea of and adjustable probe that mounts externally on the radiator. I see summit has a few to choose from. Otherwise to use a temp sending unit, i am looking at drilling a hole in either my intake or radiator, and im not too keen on doing either. So, just looking for feedback on the external adjustable style if anyone has or is using one.

my shelby dakota uses electric fans, computer controlled. the fans died, and the replacement uses a radiator fin probe, to operate. it goes into a control box that allows me to set the high/low, and it works fine. the probe is up top, near the radiator inlet. a second wire runs to the a/c compressor to run it whenever the a/c is on, but on a non-a/c car, you could use this extra circuit for a manual over ride. i've put 15K miles since the conversion, and no issues.

I have been using SPAL PWM fan controllers on my car and a few others I have done for a few years with no problems.
http://www.spal-usa.com/fans/automated/accessories/fanpwm.html

I use a Spal controller also....workes perfect. (control 2 fans with it...and use the factory sending unit to trigger it in my case, and also use a trinary A/C switch to trigger it as well)

I'm using this one from Summit:

http://www.summitracing.com/parts/HDA-3653/

I've had it in for two summers and have had no problems with it. It's adjustable and has a probe, like the one you're looking at. It just took a little playing around when I first installed it to dial it in so that it comes on when I want it to, and I haven't had to touch it since then. It's been very consistent, coming on at the same temperature (according to my temp gauge) every time. Even though this one has a built-in relay, I'm using a second relay for the power to the fan, figuring that the thermostat will last longer if I'm not running high amps through it.

what is the advantage of having it shut off?

My two electric fan (non-factory) cars have different setups. The daily driver Supra has a Flex-a-lite 220 puller with a DC Control FK 35 controller. Temp probe is near the bottom tank, but at the side away from the radiator outlet. Also bought the fan operation indicator light with the kit. Some say to put the probe at the rad inlet, but I saw no need to have the fans run every time the thermostat opened. The temp gauge sits rock steady once it reaches temperature, and the fans only run occasionally at speeds above 35 mph, except in hot weather. Been in there 8 years with no problems.

The RR has a Flex-a-lite 480 puller fan with their controller. The probe is right at the radiator inlet, per the instructions. Might move it, depending on how it behaves once it's driving. But the few times I've run the engine, they've worked as advertised.

Both controllers are digital control, they control the fan motors by digitally turning the power to the fans on and off to slowly ramp up the electrical load, rather than simply turning them on and spiking the current draw on the electrical system.