Les, the unique wiper delay relay has a built in IC offering two triggers. One appears to provide the three wipe on cycle when screen wash commanded. The other is activated by the wiper delay selection providing a varying off period. Other functions don't employ the relay.

Thankfully the whole wiper system is independent of ECU/BCU. Below is simplified diagram of similar system noting that relay has differing pin labels to the Wehrle one Morgan use.

[Linked Image]

If none of the delay selections work then break/make the two connectors at rear of wiper stalk. The smaller with just two wires provides the varying wiper delay selection to relay. Check relay connections similarly. If no improvement then replace wiper relay - Wehrle 60-201-002.

If needed I can confirm the wiper stalk is a Lucas STC4016 which could also be the culprit.

Please PM with email if you require a more detailed description of wiper workings for later Classics.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone