Hi all looking for some guidance on my focus. I've just got it back after having the thermosat changed ( works perfectly now ) but its come back with rev counter not working ( definitely worked before it went it). I wonder is there something that could of been knocked/ disconnected in the process of changing the thermosat? I know the garaged also removed the head light an whatever else in that area, not sure why they needed to like!!! I would rather not take it back to the garage as was done on mates rates threw a friend of my inlaws.

ive just been out and started car and run the test page. rev counter was working and was showing on test then all of a sudden both went off. also then noticed I had engine management light on, plugged it in an showin p0335 , crankshat sensor I think it was. Are there 2 of these? could they be put back on the right way? thanks

https://www.obd-codes.com/p0335

first thing I would do is check the connector on the crank sensor, unplug, plug back in with a bit of a twiddle of it in case just a bad connection.  they might not have done anything as such with it, they may just have knocked the connector whilst working near it and any dirt/corrosion or whatever in it might now be causing a bad connection due to it being disturbed. 

thanks, tired that! going to do a new post with more info as its now off the road in limp mode!