I'm installing a digital thermostat on my swamp cooler where
previously there was only a six-position manual switch, the normal
factory type (high/low fan, high/low cool, pump and off).
Normally, apparently, there are four wires coming from the swamp
cooler: power, pump, high fan and low fan. Indeed, the manual of the
new thermostat detail how to wire the new thermostat from these four
Well, after much frustration, I cracked open the junction box on the
cooler and found that one of the four wires is terminated immediately
once inside the cooler assembly, connected to nothing! Now, this
cooler has functioned perfectly for years, and I'm wondering how it
could have without one of its four wires connected.
Any help explaining this and/or helping me to get the new thermostat
working would be much appreciated.
Here's the specs for the new thermostat: