I have had my vectra 1.9cdti 2005 since June last year and ever since i have had it i get the annoying yellow spanner light flashing on and of randomly at various times whenever i am using the car, i have had it hooked up to my opcom many times and the same faults keep showing
there is normally one re cruise control switch malfunction (cruise works perfectly and has never not worked and i use it every day), door switch fault, if i play around with connectors and clean them ie steering colum and instrument cluster the spanner light might stay out for a few days then come back.
I decided to remove the instrument cluster (remove trim strips below air vents and unclup instrument cluster cover to gain access to torx screws for instrument cluster) and i then cut slid a piece of jet black shiny card from a soup carton under the speedo counter dial to go between the display and the dial plastic square cut out window, i replaced the instrument cluster plastic glass and hey presto i cant see the anoying warning anymore and you cant tell the card is over the display unless you really study it!!
I know i will have lost some warnings that this display shows by doing this but it was distracting me when driving especially at night so it had to be done!!
some may not agree with this tactic but it was seriously doing my head in and short of pulling every connector in the car and cleaning it i had run out of ideas!!