From inside (document excerpt):
Inducer Motor Replacement Kit Cancels: IIK 373L-55-2 IIK 373L-55-3 5-1-94 Installation Instructions Part No. 318984-752 NOTE: Read the entire instruction manual before starting the installation. SAFETY CONSIDERATIONS Installing and servicing heating equipment can be hazardous due to gas and electrical components. Only trained personnel should install or service heating equipment. Untrained personnel can perform basic maintenance functions such as cleaning coils or cleaning and replacing filters.
All other operations should be performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels attached to the unit. Follow all safety codes. Wear safety glasses and work gloves. Have a fire extinguisher available. INTRODUCTION This instruction covers the installation of the inducer motor replacement kit Part No. 318984-752 in models 373LAD/LAV, 376AAW/BAW/CAV, 383KAD/KAV, 394HAD, 395AAW/BAW/CAV, 396HAD, 58DHB/DHC, 58DFA/GFA, 58PAP/RAP, 58PAV/RAV, 58SC/SSB/SSC, 58WAV/ZAV, GA1AAD, GA2AAD, GB1AAV, and GB3AAV Gas Furnaces. DESCRIPTION AND USAGE The inducer motor replacement kit can be used for repairs (or upgrades) to the inducer motor assembly on ONLY the models listed in Step 2, item 6. The inducer motor replacement kit contains the following items: Inducer Motor Assembly Harness Adapter (Molex) Harness Adapter (AMP) Installation Instructions INSTALLATION Step 1–Remove Inducer Motor Assembly 1. Set room thermostat to OFF and allow system to complete any blower off delay. 2. Turn off gas and electrical supplies to unit. 3. Remove blower and control access doors. 4. Unplug inducer motor. 5. Remove 3 assembly mounting screws and remove inducer motor assembly (motor, wheel, and mount) from inducer housing. Be careful not to damage inducer wheel during removal. 6. Measure location of wheel to motor support to use when reassembling. Using an allen wrench, loosen inducer wheel setscrew, and remove wheel from motor shaft. (See Fig. 1.) NOTE: If it is difficult to remove the wheel, lightly sand any scale or rust buildup from end of motor shaft. Apply a small amount of penetrating oil to shaft and hub. Tap lightly on hub only. 1 Do not tap or pry on any other areas of wheel. If the wheel cannot be removed without damage, a replacement wheel is required. 7. Remove 3 motor grommet screws securing motor plate to motor support. 8. Remove 2 screws securing motor to motor plate. Step 2–Install New Inducer Motor Assembly 1. Attach new inducer motor assembly provided in kit to motor plate using original screws. 2. Attach motor support to motor plate through 3 grommets using 3 original screws. (See Fig. 2.) If there was a shaft seal between the plate and support, be certain it is moved to the new assembly. Tighten original screws firmly, but avoid stripping. 3. Reinstall inducer wheel. Wheel must be located as shown in Fig. 1. Align flat on shaft to line up with setscrew, then firmly tighten setscrew. 4. Install inducer motor assembly in inducer housing and fasten with 3 original mounting screws. Ensure that inducer motor ground wire is reinstalled under 1 of mounting screws. NOTE: The 3 original mounting screws are shorter in length than the other screws. Use of longer screws may result in interference between the screws and the inducer wheel. 5. After all screws are tightened, spin black plastic cooling fan to ensure assembly moves freely. If assembly does not spin freely, remove inducer motor assembly from inducer housing and verify correct location of inducer wheel on motor shaft.