Greydog

Has anyone come across this problem before period internal blowers demister for front windscreen the max button air conditioning button etc do not seem to work but this is only intermittent occasionally I get into the car and it will work and continue working for for a few days then stop then it won't work again for another few days then start working again period the back demister works absolutely fine so I cannot decide what is going wrong whether it is a loose wire or something like that does anyone have any ideas