The climate control panels on some of its 2001 Volvo S40 and V40 models may cease to function for no apparent reason.
According to the Swedish car maker, the problem is often intermittent, and is most likely due to voltage spikes being introduced into the panel by the blower motor.
Installing a specially designed adapter harness with a built-in suppression diode, part No. 30858845, between the blower motor and its connector should eliminate the problem.
"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].