The Joe Cool unit provides a time-delay for the cooling fans, so that the compressor and fans do not all start at the same time, resulting in less amp stress and less chance of failure in the electrical system. That is generally how it works, there are better descriptions that you can look up...basically, I think it is magic.
|Joe Cool (Snoopy) with Peanuts Gang
|Joe Cool with Peanuts
|Relay compartment, before installation.
|Close up of the relay compartment, before installation.
|Removed the two modules. The two plugs of the new unit will go here.
|Sequential Fan Controller installed.
|Joe Cool Snoopy 'installed' in DeLorean.