Coolit H2/H3 C5 Corvette High-Speed Fan Controller Kit

Because of the high demand on the Coolits, there is a 1-4 business day shipping lead time.

Coolit H2/H3 Hard-Wire Fan Controller Kit

Hard-wired control for serious cooling performance. The Coolit H2/H3 is designed for C5 Corvette owners who prefer a hard-wired fan controller instead of the wireless Coolit V Series. It operates like the original wireless system but uses a switch with an integrated LED light to activate the right-side radiator fan in high-speed mode and also lets you run the Fan with the ignition On or OFF.

Key Benefits

The Coolit H2/H3 gives you direct control of your C5 Corvette’s high-speed radiator cooling fan with the push of a button. This allows you to manage coolant temperatures without paying for an expensive tune just to change fan on/off settings.

• Activate the right-side cooling fan in high-speed mode from your installed switch.
• Use the fan even when the ignition is off, making it ideal for track use and cooling down in the pits.

          (Reminder: Turn your fan off when you park your C5 so the battery won’t run down.)

• Keep coolant temperatures under control during hot laps, traffic, parades, or extended idling.
• Help keep automatic transmission temperatures cooler.
• Avoid turning on the A/C just to bring engine temperatures down.
• Confirm fan operation at a glance with the integrated LED indicator.
• Enjoy the strategic advantage of keeping your cooling fan active over 35 MPH, countering the factory default where the computer normally doesn't allow the fans to come on at speeds over 35 mph. So if you are in traffic cruising at 36mph the fans won't be on, and that is not enough air flow to stay cool on a hot day.

Designed for Easy Installation

The Coolit H2/H3 was developed to be as plug-and-play as possible. Once installed, the switch gives you quick manual control over the right-side cooling fan whenever extra cooling is needed.

Factory-Compatible Operation

The Coolit H2/H3 will not interfere with the normal computer-controlled operation of your cooling fans. Your factory fan system continues to operate as designed.

Quality Construction

The Coolit H2/H3 uses your C5’s factory wiring to run the high-speed fan. Each kit is built with high-quality components, including a factory relay rather than an aftermarket or copy. Connections are soldered and/or hydraulically crimped for dependable long-term reliability.

Why It Matters

Installing the Coolit H2/H3 helps improve cooling control, performance, and reliability for your C5 Corvette. Whether you are hot-lapping at the track, cooling down between runs, sitting in traffic, or idling during a parade, this high-speed fan controller is an affordable must-have accessory—because cooler is better.

Note: The Coolit H2/H3 will not fix existing overheating issues.

Proudly made in the USA!

Click here to see if you need a H2 or H3

Click here for full PDF installation instructions.