Rear wiper motor failing or RLS?

I think my rear wiper motor is failing as I know its a common problem. But before I go to the hassle of stripping it down, and the potential cost of replacing it, is it possible it is to do with my rain and light sensor (RLS)?

It may be coincidence but it seems to work fine when stationary and no front wipers are on, and only when I am driving does it appear to fail by running three or four times and then stopping until I cycle the switch off and on. So could this be to do with my RLS?

I ask because there is an intermittent fault code on my RLS (01520 - Rain and Light Recognition Sensor (G397)) for which the RT wiki is not overly helpful:

http://wiki.ross-tech.com/wiki/index.php/01520

I guess the question is does the rear wiper get controlled by the RLS in any way?

Thanks in advance

Adam

Edited 4 January, 201610 yr by adamal