The turn signal is controlled by a multi-function switch on the left side of the Turn Signal Switch. In addition, headlight dimmer and windshield wiper/washer are also operated by this switch. For checking of its functionality place it back and using an ohmmeter or a self-powered test lamp to check for any continuity between two terminals on/off position as indicated in the switch; if the continuity is not as is required then the switch will need to be replaced. For replacement first shut down the car and disconnect negative and positive terminal of the battery for at least 2 minutes. You should then take out the 
Ignition Lock Cylinder and the steering column covers, then the rest of the screws and connectors to pull the switch off the steering column and that a later model involves a tab that will need to be pulled in order to disconnect it. Installation takes place in reverse order to the removal. With regard to cruise control switches, one should open the hood to get to the cruise control speed amplifier servo, then wrench off its electrical connection and use an ohmmeter to measure the resistance between the mentioned terminals on each switch position; if resistance is not standard the switch should be replaced. Start the replacement by unbending the battery cables and waiting for two minutes; Here, one has to unbolt the driver's side 
Air Bag module from the steering wheel. Subsequently, the cruise control actuator switch retaining screw is to be unscrewed, the electrical connections to be severed and the switch to be separated from the steering wheel and for all these procedures the reverse process of removal is to be adapted for installation.