Restore multiple speeds to your auto heater/air conditioner blower by replacing a resistor module. It’s a simple, quick change-out.
By the DIY experts of The Family Handyman Magazine:June 2008
Remove the electrical connector, retaining screws and the old resistor module. Swap in the new part and reinstall the screws and connector.
Most car manufacturers use a series of resistors to make the heater blower motor run at different speeds. And when one or more of these resistors burn out, you're usually left with only one blower speed—high. The resistor module is easy and inexpensive to replace. It's then typically installed in the ductwork, near the blower—either under the dash or under the hood. (Refer to a service manual to locate yours.)
Purchase a new resistor module at the auto parts store (usually less than $25). Disconnect the electrical connector. Remove the screws, and swap out the resistor module. Reconnect the electrical connector and you're back in business.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
You may also need a trouble light.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.
