I have a 1997 E320. The A/C and heater with the climate control work. The fan speed only goes from off to medium. Another post said that it could be the speed regulator for the blower motor. Does any one know how to check the speed regulator and replace it if necessary? I know how to access the area under the glove box where the blower is locsted. Is this a repair I should take to the shop?

 

check voltage output to the blower from regulator.