Component Tests: Relays
WARNING:
Deactivate air bag system before performing any service operation near steering column. See
AIR BAG RESTRAINT SYSTEMS - TRUCKS article.
- Remove suspect relay from vehicle. See COMPONENT LOCATIONS . Using an ohmmeter, check for continuity between relay terminals No. 87A and 30. See Fig 1. If continuity does not exist, replace relay. If continuity exists, go to next step.
- Check for continuity between relay terminals No. 30 and 87. If continuity exists, replace relay. If continuity does not exist, check resistance between relay terminals No. 85 and 86. If resistance is not 70-80 ohms, replace relay. If resistance is 70-80 ohms, go to next step.
- Using jumper wires, connect positive battery voltage to relay terminal No. 86 and ground to relay terminal No. 85. Continuity should exist between terminals No. 30 and 87. Continuity should not exist between relay terminals No. 87A and 30. If continuity is not as specified, replace relay. If continuity is as specified, relay is okay.