If performance is more important than price -
recommend the Flex-A-Lite VSC
. (Part# 31165-VSC)
One of the improvements of the Variable Speed Control is its soft-start feature that prevents the fans from drawing a large surge when they spin up. It's much less stress on the electrical system, especially with trucks using two large fans with a combined total of 5500 cubic feet per minute of flow!
- Also reducing stress on the electrical system, the VSC will not power up the fans for a 5 second delay after ignition.
- When the VSC starts the fans it powers them at 60% speed reducing noise and power draw. If the coolant temperature continues to rise, the VSC will increase fan speed gradually to 100% over the next 10 degrees beyond your calibration point.
- The air conditioner clutch will also activate the fans at 60% power unless coolant temperature is higher than the calibration point and the fans are already running at a higher speed.
- The VSC will continue to run the fans for up to 30 seconds after shutdown if the coolant temperature in the core is sufficient. (This feature will prevent post-shutdown boil-over in high-temperature applications.)
- The manual override ON input allows the fans to be turned on at 100% speed at any time, regardless of temperature or AC status, as long as the ignition is on. The engine does not have to be running. (This will be especially handy at the drag strip!)
- The manual override OFF input will prevent all other inputs from starting the fans. (The ability to disable the fans is a nice safety consideration if work must be done in the engine compartment while the engine is running. Electric fans can surprise you coming on without warning.)
Available at JEGS.
This is what I used before the Haltech controlled the fans.
It worked more efficiently with the variable speed, and the 30 seconds after shutoff feature.