Out driving today in the wet, just wet enough to need the intermittant wipe. when it got heavy the speed kicks in. It was speckling the screen and adjusting the thing on the stalk from longer to shorter made no difference it kept swiping at the same rate.

Ideas on where i need to look or what to replace please.

mine auto speeds up when the rain is heavy could that be it ? when rain slows down so do the wipers

i get the speed up bit when it rains harder, but when its occasional spots adjusting the thimb turn on the stalk does not increase or decrease the wipe rate, am sure it used to.

My auto wipers can be a bit flaky at times, and will just default to wiping every 7 seconds or so despite the stalk setting. I think something locks up in the GEM or the software. 
 

In the past I’ve reset the GEM using elmconfig, I think that helped. Just a general module reset not reloading software or anything that severe. 
 

But these days I just live with it and it seems to sort itself out eventually. 

On cars with auto wipers, the thumb wheel only adjusts the sensitivity, not the wipe rate directly.  So if the rain is very fine, or the spots are wide apart, the sensor may still not be able to detect it correctly.

On cars without auto wipers, the thumb wheel does increase the wipe rate directly.

 

cheers guys thanks for the replies, one less thing to fret about