SC300 & SC400
- Turn ignition off. Disconnect 14-pin combination switch connector "A" and 18-pin combination switch connector "B". Using an ohmmeter, check continuity between connector "B" (harness side) terminal No. 4 (White/Black wire) and ground. Also, check continuity between connector "B" (harness side) terminal No. 18 (White/Black wire) and ground. If continuity exists at both terminals, go to next step. If continuity does not exist at either terminal, repair wire harness between combination switch and ground connection. Retest system operation.
- Using an ohmmeter, check continuity between connector "A" (harness side) terminal No. 10 (Green/White wire) and connector "B" (harness side) terminal No. 1 (Green/White wire). If continuity exists, go to next step. If continuity does not exist, repair wire harness between combination switch. Retest system operation.
- Turn ignition off. Reconnect 14-pin and 18-pin combination switch connectors. Turn ignition on. Using DVOM, measure voltage by backprobing rear of combination switch connector between the following terminals and ground with light control/dimmer/foglight switch in specified position. See LIGHT CONTROL/DIMMER/FOGLIGHT SWITCH CIRCUIT VOLTAGE (SC300 & SC400) table. See Fig 1. If voltages are not as specified, repair wiring harness or replace components as necessary. If voltages are as specified, check combination switch. See COMBINATION SWITCH under COMPONENT TESTS. Replace combination switch as necessary. Retest system operation.
LIGHT CONTROL/DIMMER/FOGLIGHT SWITCH CIRCUIT VOLTAGE (SC300 & SC400)
| Check Voltage Between Ground & Terminal No. | Switch Position | Voltage |
|---|---|---|
| A10 | HEAD, Low Beam & Fog Light Switch ON | Zero |
| A10 | HEAD, High Beam Or Flash & Fog Light Switch ON | Battery |
| A11 | OFF Or TAIL | Zero |
| A11 | HEAD | Battery |
| B7 | Any Position Except Flash | Battery |
| B9 | OFF Or TAIL | Zero |
| B9 | HEAD | Battery |