I have a 94 Chevy 2500 HD pickup. I get a clicking sound down by the heater fan for about 20 sec when I turn the truck on and off. I have been told it was my blend door actuator and it needs to be replaced. Can anyone tell me the best way to go about this or if you think it's something else. Thanks

 

Check the fan moter it self first,it might just be something in the houseing hitting the blades.But if it is the actuator that is clicking this means that it is slipping,so this should make the heat vent only work on the setting that they are stuck on or are very slow to respond to the setting you switch it too. There are 2 spring that fit into slots on the arm of the actuator and they both or one might be getting bad also. To check this ,you have to lie on your back on the floor of the drivers side and look up at about the center of the dash almost behind your setting controls.You should be able to see the two springs inside the hollow squares if they are there.
And if you have to change the actuator it self,you have to remove most of the dash to get to it.It is not hard to do but it is time consumeing.