O'Fallon Auto Repair

The Tiny Switch That Runs Your Car If you have ever flipped a light switch in your home, you understand the basic idea behind a relay. It is a switch, but instead of your finger doing the flipping, electricity does the work. In your vehicle, relays are everywhere. They hide under the hood, behind the dash, and in fuse boxes you may never have noticed. At Hillside Auto Repair, we see relays controlling everything from your fuel pump to your headlights to your cooling fans. They are small, inexpensive, and absolutely critical. When one fails, the symptoms can be baffling. A car that will not start or a fan that will not spin often sends drivers in O'Fallon searching for a major mechanical problem when the real culprit is a tiny switch the size of a matchbox. How a Relay Actually Works A relay is an electromagnetic switch that lets a low-current circuit control a high-current load. Inside the relay housing, a small coil of wire creates a magnetic fie ... read more