Electrical Test - Standard System
- Check all fuses and connections. Adjust brake release valve and switch. Disconnect switch harness 3-wire connector at lower end of steering column.
- Connect an ohmmeter between Brown and Blue wires. Continuity should exist until switch is pressed in completely. Connect ohmmeter between Brown and Black wires; continuity should exist only when button is halfway depressed. Connect ohmmeter between Blue and Black wires; continuity should exist when button is depressed both halfway and completely.
- With switch disconnected, remove battery ground cable. Connect ohmmeter between Dark Green wire and ground. Resistance should measure 42-49 ohms. If not, check transducer ground connection and measure Dark Green wire between switch connector and transducer. Resistance should measure 38-42 ohms; if not, replace wiring harness.
- Measure between transducer "Hold" terminal and ground. Resistance should be 5-6 ohms. If not, check ground connection and replace transducer if necessary.
- Connect ohmmeter between terminals on brake switch. Continuity should exist with pedal released, and infinity when pedal is depressed. If not, replace switch.
Courtesy of GENERAL MOTORS COMPANY