Clio Mk 3 Wiper problems

I have an annoying fault with the wipers on my 2009 Mk3 Clio. The first problem was no intermittent and slow speed on full. I thought it was the motor so switched it out that didn't cure it. Turned out to be a seized mechanism, so after much WD40 and some gentle heat I freed it all up. Now slow and fast speed work fine but no intermittent. Both the original motor and the replacement one I bought show the same fault, so I think it's else where.
Any suggestions what and where to look next ? - Thanks

Clio Mk 3 Wiper problems