The owner of a 2005 Ford Thunderbird or Lincoln LS model with a dual zone climate control system may come into your store with a complaint that his blower motor isn't functioning.
One possible cause, Ford said, is a blown blower motor speed controller.
To confirm the diagnosis, disconnect electrical connector C297 from the speed controller. Next, using the illustration above, connect a 30-amp fused jumper across terminals 1 and 2 of the connector.
Now turn the ignition switch on. If the blower motor still doesn't work, continue troubleshooting until problem is resolved.
If the blower motor operates with the jumper installed, that verifies that the speed controller is blown. Installing a new-design controller, part No. 3W4Z-19E624-AB, should eliminate further trouble.
"Factory Fixes" is written by Jim DePalma, a 30-year veteran of the auto repair business who has served stints as a service manager, parts manager and ASE-certified technician. His column provides vehicle manufacturers' authentic factory technical service bulletins (TSBs) that have been condensed for easier reading. Mr. DePalma advises that techs always check with a dealer or repair information system for the latest revisions before starting to work on a vehicle. He can be reached via e-mail at [email protected].