Mk 2 problem..........please help!!!!

Rev counter works fine until i turn on my lights then it drops to half what it should be reading, if then i try to dim the dash board lights the rev counter goes all together!
thinking it might be a bad earth but not sure where to look for it
any help will be much aprieciated
JIM

Heard the strap to the rocker cover/head on a mk1 gti can cause a fault like that. Not sure on a mk2 but I'd clean all the earth points up in the engine bay and see how you get on.

cheers tom, will try that

one frm starter to the car is normally the culprit

check the rear of Rev Counter if u got tiny circuit board on ur type the diode often burn out . Trx new light switch my Rado had simlar fault. Good luck