tach/speedo intermitantly not working

i just bought a 95 Jetta III and the tach and speedo don't work about 50% of the time. The miles seem to work properly regardless and the gas and temp gauge work fine. what do i need to fix in orfer to keep them working constantly? any help is much appreciated thanks!! I dont have internet use regularly, so please email me at [email protected] if possible!

I have a 95 jetta III and have the same problems. My temperature gauge does not work, either. Anyone can give a hint?