HiLetgo2pcs W1209 with Case 12V DC Digital Temperature Controller Board Micro Digital Thermostat -50-110°C Electronic Temperature Temp Control Module Switch with 10A One-Channel Relay and Waterproof

Using this temperature controller with computer fans installed in a boat solar charging system. They are easy to set and keep switch the fans on or off as the temperature in the battery and charger controller compartments rise or fall. Very accurate and reliable.

I used this as a fan controller for my motorcycle. I put the sensor into the radiator fins and dialed in the temperature I wanted to see on the temp gauge. The fan comes on and goes off precisely and crisply compared to the thermo switch that was impossible to find for an older bike. It now starts the fan smartly as opposed to groaning to life with the thermo switch. Just connect the device (+) source power to the running light circuit which comes on when the engine is running. For the fan, provide frame ground, and positive from battery, then through 10A fuse, then through switched relay onboard the device to the fan positive. The programming is simple if you google the device specs on YouTube.

work well to control a fan

Brought two controllers, but have only used one so far. Wired it up to control an extra cooling fan for my RV fridge. Works well, although kind of a pain to program. Biggest hassle is having to convert the temps to Fahrenheit. No way (that I found) to make the controller use Fahrenheit temps. No big deal once you get it set up. If you have problems programming it, there's plenty of help on YouTube. Overall, a good, inexpensive controller that works well.

I only got one in the package. Was supposed to come with two.And waterproof lol. It should come with a tube of silicone if you’re gonna try to say it’s waterproof cause that what you’ll need to use. I’ve used these before and they work good is the only reason I didn’t send it back.