Alfa 147, 156 & GT
travelling at 60mph, turn wipers to intermittent, each time the wipers activate the speedo dips from 60 to 0
also when the cabin fan is set to 3 it dips & at 4 it goe sto 0 to stay there.
connections to the back are good.
i'v etried a 2nd speedo, same issue
'earthing' springs to...