Just a bit of possibly useful info as I spent more time then wanted on this one. There are plenty videos and posts on this but a lot of people complain that the next test drive after tackling the job the light comes back on. Cutting a long story short my fault was the dreaded spring coming undone in the imrc unit. The problem I found when I opened it was I could not see where the spring is meant to go (as it’s a bad design). If you look at pictures on google you’ll find where people chemical metaled them into place. Now this is why I am posting where the spring goes at first glance the spring is not acting (THIS IS WHY THE LIGHT IS BACK ON AFTER FIRST DRIVE) the trick is to preload the spring. Turn the final gear fully clockwise until it stops then attach the spring when you turn it back you will see the spring acting on the cable. This may be common sense to some but all I can find on the net is people’s lights coming on after attempting. Took me a bit to figure it out as when you look at it there is nowhere obvious for the spring to go (no holes or cutouts etc) and if the spring does not look like it’s acting then it’s not lol 😂

Right here again eating my words lol. Above info still nice to know but the spring came off on my first test drive 😂 The most common fix seems to be chemical metal but I’ve never used it my self. Pictures available with google search. Think I’ll try that and I’ll be back if it doesn’t stand the test of time.

Back again. Long story why I took so long but got around to her today. I used metal epoxy as it was really cheap and I’m nuts deep in the car already. Just back from a test drive and what I found was she definitely climbed the rev range much faster. My advice if your using this stuff is give it every chance to work, but test that it stuck properly before you close the unit. A lump of this stuff will eat the gears quick fast if it comes free 😂. Best of luck to anyone with this fault. It’s an easy fix so don’t be afraid to try. Loads of stuff there on google and YouTube. I picked up a real hand tip get rid of the knuts holding on the unit as they need to be turned off fully with a spanned. Then grease the threads and fit normal knuts! Makes fitting and removal a walk in the park.

Does anyone have a pic of the correct position of the return spring, attached to the white plastic cam please? Also, the transistor that frequently goes, does anyone know the spec or part number of this transistor please? I've tried the basic fixes but so far my IMRC I still not working and I'm due a MOT next week and since the law changed in May, engine lights on are a fail!