D 150 Ramcharger V8-360 5.9L (1989)
Wiper Switch: Testing and Inspection
Fig. 11 Two Speed Wiper Switch Continuity Chart
Fig. 12 Intermittent Wiper Switch Continuity Chart
1. Disconnect electrical connector to switch at body wiring harness connector.
2. Operate switch in all positions, and check continuity between terminals with an ohmmeter. The first (clockwise) position is the Off position.
Next is the slide for the Delay wipe, with counterclockwise rotation, reducing the delay. Low is the next detent position. High is the full
counterclockwise detent position. In any wiper mode, if the knob is pushed in all the way, the washer circuit will be completed.
3. If continuity is not as specified in charts, replace switch.