You won't find a separate "intermittent wiper pulse board." Troubleshooting intermittent wiper problems on this vehicle would involve checking:
* The combination switch: This is the most likely culprit. A faulty switch can cause intermittent problems. Testing its internal circuits might require specialized tools.
* The BCM: The BCM controls many electrical functions, including the wipers. A malfunctioning BCM can cause various electrical gremlins, including wiper issues. Often diagnosis here requires professional equipment.
* Wiring: Check the wiring harness for breaks, shorts, or corrosion, particularly between the switch, BCM, and the wiper motor.
* Wiper motor: Though less likely to cause intermittent issues, a failing wiper motor could also contribute to the problem.
In short, there's no single "board" to replace. Diagnosis requires systematic troubleshooting to identify the faulty component. A repair manual specific to your 1996 Dodge B2500 would be extremely helpful.