The control relay switch is an electronic component that controls the power supply to multiple switches inside your car. When a control relay switch sticks -- in either the open or closed position -- it effects the electronic controls of the automobile; several different problems can cause a control relay switch to stick.
Anytime a control relay switch becomes corroded, the switch will stick in the open or closed position. If corrosion builds up inside the switch, the relay generally remains locked in its original position; the control relay switch will then quit working properly.
A control relay switch has several contact points; no voltage is running through the relay when the contact points are in the open position. These contact points are wearable components and, over time, can become melted together; this causes the switch to remain in the closed position.
The contact points can also wear instead of becoming melted together; electricity makes a spark when the contact tips come into contact; this spark will slowly deteriorate the contact points, which will wear the contacts. A worn control relay switch contact will quit making a voltage connection. If the voltage cannot travel through the contact points of the control relay switch, the relay stops working. Worn contacts will prevent the voltage from flowing through the relay switch.
Low voltage can also cause the control relay switch to stick. When voltage is taken away from the control relay, the switch remains in its original position. Electrical current flows through the wires running to the control relay switch; if the current is interrupted or stops flowing through the wires, the relay switch will get stuck.
