AC Clutch AND AC COMPRESSOR INSTALLATION RELATED FAILURES
The following are the most frequent causes of installation related AC clutch failures. Please note that AC clutch failures resulting from improper installation are not warrantable.
A:Loose Field Coil Mounting Bolts If the bolts used to mount the field coil are not tightened adequately, vibration in the vehicle will cause the coil to become loose. Eventually the field coil will begin to contact the rotor assembly, as evidenced by rubbing on the field core outer diameter. This rubbing may generate heat that melts the field coil epoxy, leading to an open circuit and inoperative clutch. This condition is specific to CCI/York/Tecumseh style compressors. The replacement clutches for these type of compressors are now normally supplied with special locktite treated fasteners. Use of these fasteners normally solve this kind of problem.
B:Short or Open Circuit in Field Coil Wire If the clutch lead wire is routed in such a way as to subject it to possible rubbing or cutting by another object, the wire insulation can be rubbed through and the bare wire exposed. A short circuit or open circuit will likely develop, causing the AC clutch to become inoperative. This type of failure is evidenced by a lead wire worn down to bare metal in one or more locations along it length, or a lead wire that gets cut in half.
C:Shaft Key not Seated Properly in Armature Hub If the key is not properly inserted into the keyway on the compressor input shaft during a clutch installation, a severe misalignment of the pulley relative to the shaft will occur. This misalignment will create interference between the rotor and field coil assemblies. Evidence of severe rubbing of the pulley on the field coil will be present.
D:Improperly Installed or Wrong Snap Ring Use of a wrong snap ring, or an improperly installed snap ring on the field coil or pulley can cause the clutch to be noisy, fail to disengage, or in some cases come off. Resultant clutch damage can follow. This is especially true on some Ford FS6 compressor clutches, where several types and thicknesses of snap rings were originally used. Consult manual for further instructions.
E:Mismatched Clutch Components Especially in the case of Ford FS6 and FX15/FS10 type clutches, complete replacement of the clutch and coil assembly is required. Original or replacement Ford O.E. clutch components cannot be mixed with aftermarket type clutch components (such as a Ford O.E. coil and an aftermarket pulley and hub). Mixing these different types of components together can cause clutch failure and/or faulty clutch operation.
F:Improperly Installed Coil Ground Wire On CCI/York/Tecumseh style field coils, the ground wire terminal should be installed on top of the coil mounting flange. If the terminal is improperly installed underneath the flange, the alignment of the outer coil and inner pulley interface will be adversely affected and create the potential for rubbing between the rotor and coil assemblies.
G:Use of Excessive Torque on Compressor Shaft Mounting Bolt Broken or twisted bolts are the result of excessive torque applied during installation, such as from use of an impact wrench. Check manufacturer torque specifications when installing AC clutch hardware.