Chrysler Repair: noise in heater fan, automatic temperature control, chrysler new yorker

Question
I have a 1994 chrysler new yorker.  When I turn on the heater fan I get a clicking noise like somthing is hitting the blades but after a few seconds it goes away.  The noise intermittently returnes on its own or whenever I change speeds.
any Ideas?

Thank You


Answer
Hi Richard,
I suspect that there is some wobble or misalignment in the fan rotor so that it is hitting the shroud which surrounds it. The fan and motor are on the right end of the unit (assuming this is normal unit for A/C-heater, not the automatic temperature control type unit) and you can get to that motor and rotor by removing the glove box*, then disconnect the two vacuum lines and the motor electrical connector, remove the two screws that attach the blower housing to the unit's cover. remove the 5 screws around the blower housing and separate the blower housing from the unit, remove the 3 screws securing the blower and rotor wheel assembly to the housing and separate the assembly from the unit. You can then put 12V on the motor plug and observe the motion of the rotor. It may just need a slight bending to straighten it. The procedure above is taken from the Chrysler shop manuals for '89 and '94.
I have had a similar situation with my other car (a '67 BMW) but have just learned to live with it as I don't have the enthusiasm to tear into the unit in exchange for silencing an intermittant noise like you describe. But at least you can do it yourself if you choose.
Roland  '89 LeBaron Coupe
*glove box removal: remove glove box lamp and disconnect wiring, pull deck lid release switch out of glove box and disconnect wiring, remove 7 screws around glove box edge, then remove the glove box assembly.