The Viper K2 Deluxe light (the one with the fan and moonlights) has a SERIOUS design flaw. The fan, while it has its own hi/low rocker switch, takes its power from the ballast, which has only one power cord.
The problem is that if even if you run the light on a timer or controller, you cannot control the fan with one. You have a choice: either it's on the entire time the light is on (which in my firsthand experience will cool the tank TOO much), or it is off all the time, in which case you might as well throw the fan in the garbage. I guess you could say option 3 is you could stand by your tank all day and turn the fan on or off as needed, but I'm a touch busier than that.
The fan should have had its own power cord. Since it doesn't, the only fix is to add one for it.
All that is needed is a cord (which I cut off of an old dead powerhead) and a few minutes time.
Take the top off the ballast. On the back of the fan switch are three wires: one red on the center terminal and two blacks (one for high, one for low). The red/center wire is the main positive wire for the fan, feeding the switch its 120v power. It is wire-nutted with two other wires. Remove the one to the fan switch from this group, and wire nut the other two back together. Connect this (the red wire you removed) to the positive side of your new power cable (after, of course, you have drilled a path through the case and installed the wire and a rubber grommet).
Entering the case from the big "output" cable are four wires, some for the light and some for the fan. The BLUE wire is the neutral side of the fan. Follow the same procedure as before, removing it from its "group" and rejoining the other wires it shared a connection with. Connect the blue wire to the other side of your new power cable.
The grounds are all under a screw in the bottom of the case, just put your new ground under that screw with the others, using a crimp ring terminal.
That's all there is... now your fan has a dedicated cord so you can use a controller to turn it on or off as needed... all you have to do manually now is select high or low speed to use when it runs, and leave the switch in that position.
The problem is that if even if you run the light on a timer or controller, you cannot control the fan with one. You have a choice: either it's on the entire time the light is on (which in my firsthand experience will cool the tank TOO much), or it is off all the time, in which case you might as well throw the fan in the garbage. I guess you could say option 3 is you could stand by your tank all day and turn the fan on or off as needed, but I'm a touch busier than that.
The fan should have had its own power cord. Since it doesn't, the only fix is to add one for it.
All that is needed is a cord (which I cut off of an old dead powerhead) and a few minutes time.
Take the top off the ballast. On the back of the fan switch are three wires: one red on the center terminal and two blacks (one for high, one for low). The red/center wire is the main positive wire for the fan, feeding the switch its 120v power. It is wire-nutted with two other wires. Remove the one to the fan switch from this group, and wire nut the other two back together. Connect this (the red wire you removed) to the positive side of your new power cable (after, of course, you have drilled a path through the case and installed the wire and a rubber grommet).
Entering the case from the big "output" cable are four wires, some for the light and some for the fan. The BLUE wire is the neutral side of the fan. Follow the same procedure as before, removing it from its "group" and rejoining the other wires it shared a connection with. Connect the blue wire to the other side of your new power cable.
The grounds are all under a screw in the bottom of the case, just put your new ground under that screw with the others, using a crimp ring terminal.
That's all there is... now your fan has a dedicated cord so you can use a controller to turn it on or off as needed... all you have to do manually now is select high or low speed to use when it runs, and leave the switch in that position.
