Fuse Location (Note: some older models do not have a fuse)
Here’s a diagram of a typical back panel, some panels are organized a little different and don’t have the blue (or yellow) capacitors. The Fuse is indicated below.
The fuse can usually be visually examined to see if it is blow or burned out. The fuses are “slow blow” 2Amp, 250Volt and typically have a nylon looking core with the fuse wire wrapped around it so you have to look closely to see if the wire is broken anywhere.
Here is a close up:
You should use a multi-meter to be sure. (Set it on Ohms, it should measure a resistance of less than 5 ohms). Note, the fuse just protects the sprinkler valves and transformer from shorting; if the fuse is bad, the controller will still receive power from the battery, but the battery can’t supply enough power to actually activate the valves. It’s just intended to keep the clock going during short power outages.
Although it seems strange, if you are getting the FUS message on the display, it is usually not an indication of a bad fuse. Look in the troubleshooting options for more information about the FUS error.