I have an '01 CLK 430 cabriolet with an intermittent blower problem. The blower will sometimes start immediately, at other times it may take 10-15 minutes before it turns on. Occasionally (including right now) the blower does not work at all, although I can still feel a trickle of cold air coming from the vents. The control panel display works and when the blower decides to turn on I can adjust the speed and temp. I've read other similar posts that made reference to a relay but I don't know where it is to check it (or how to test it). One person told me I'd need to replace the blower motor and the realy at a cost of over $800. Since I just got laid off that is not in my budget, so I'm hoping for a much cheaper DIY fix. Thanks!

 

you need a new blower regulator and possibly a new blower. regulator is mounted next to the blower fan under the passenger dash. remove blower and then youll see the regulator.

 

Thanks for the quick reply about the regulator. How do I determine if I need the new blower motor? Do I need to replace the regulator and then test it?

 

on a normal basis the regulator causes that problem..usually has a weird quiet chirpping sound as its trying to work.
but the blowers can get water in them from having clogged drains and not keeping your cowl free from debris..when you remove the blower just see if it spins freely it should spin freely. obviously there could be another issue causing your problem but the regulator is common.