Recently something has broken in my heater system. Now when i go from fan speed one to two ect there is a quiet clunk in the dash, coming from the heater area. Im guessing its some kind of fan relay? because when i do so there is a shortage of power, ie lvl 3 cluster lcds dim for s aplit second. It all still works its just worrying thats all, wouold like to get it fixed! thanks!
Any ideas?

James