[PDF] 1.0 1.0 INSTALLATION INSTRUCTIONS PERFORMANCE ■ To prevent burns, install the tachometer only when the engine is cool. ■ The vehicle's exhaust is very toxic, to prevent serious injury or death always run the vehicle in a well ventilated area. ■ When an engine is running, cooling fans, pulleys, belts, etcte at a very high rate of speed. 1989 Chevy S10 - Equus Tachometer Install - Sport Truck May 01, 2008Photo 2/19 | equus Tachometer Install tachometer. Not only do tachometers look tough hanging from the dash, they also provide a needed service: monitoring the rpm. Keeping track of the Rs on your truck may not seem like a big deal unless you're a quarter-mile junkie, but it's something you should know.