The Yamaha Key Switch serves a significant purpose. This one works for the G11, G16, and G20-G22 models. It is a part of what is called the activation circuit. This refers to the series of switches that help activate the solenoid. They are directly in series with it, or they send a signal to the controller, which then activates the solenoid. On the older models, you are relaying the signal from a power source through several switches back to the solenoid. The newer models, like the G22, for example, use the controller as a routing point. Either way, this product is a vital step in the process.If it goes bad, the caddie will cease to function altogether. There is no going bad period where it will work at a resisted rate. It's working, or it's not. This golf cart key switch is effortless to replace, though. If you have ever plugged in a lamp, you are overqualified. Give Buggies Unlimited a call today.