MK4 Heater has packed up

Please help! My MK4 golf's heater started making a strange whurring noise and stopped. Then it started again after 10 mins or so. It is very intermitant. I can be travelling for 5 mins and all of a sudden it will start and then 5 mins later it stops. This goes on all the time. With the way the weather is at the moment and the fact my girlfriend usually drives it, I need to get it sorted ASAP. I have stripped the switch mech. and cleaned the contacts. When I put it back together it worked and I thought I had fixed it -then it stopped! Has anyone got any ideas?

Cheers

sounds like a bad blower motor

sounds like a bad blower motor
Is this blower motor easy enough to replace?

Is this blower motor easy enough to replace?

yup, 2 8mm bolts right above the lower pannel on passenger side. Might want to remove the side dash pannel on that side (prys off) to get a better look at the connector.