How to Fix Intermittent-Wiper and Turn Signal Problems on the Multifunction Switch
In late-model cars, turn signals and intermittent wiper controls are the most common failures on the multifunction switch. Doing the repair yourself isn’t as complicated as it looks-and it’ll save you money!
Common Problems with the Multifunction Switch
Once known as a turn signal or blinker switch, the multifunction switch lever now also controls headlights, high beams, emergency flashers, wipers and washers. No wonder it’s called the multifunction switch (MFS) these days. Unfortunately, the MFS has a fairly high failure rate. The two most common failures are a broken turn signal “canceling” mechanism that won’t shut off the “blinkers” after a turn, and a partial or complete loss of intermittent wiper control. To fix these two problems, you’ll need a shop manual, a digital multimeter and possibly some Torx bits.
On most late-model vehicles, the MFS is located under the plastic covers behind the steering wheel. In that case, you can do this repair in about an hour and save the cost of an hour or two of shop time by doing it yourself. But some older vehicles require the removal of the airbag and steering wheel, and that’s a job for a pro. Refer to a shop manual to see where your MFS is located (you can find shop manuals with an online search).
Always disconnect the negative battery terminal and wait 15 minutes for the airbag system to power down before starting work on the steering column. Then remove the screws and lift off the plastic covers.
The MFS is usually held in place by hex-head or Torx screws. Remove them, pull out the switch and disconnect the electrical connector. If the problem is a broken canceling mechanism, you must replace the entire MFS (source a replacement from an auto parts store or dealer). If the problem is faulty intermittent wiper operation, use a multimeter to check the connectors on the back of the MFS for resistance (ohms) readings for each setting on the intermittent wiper dial. Then compare them with the manual. If the resistance readings are off, the shop manual will tell you to replace the MFS. But you may be able to save big bucks by disassembling the MFS and cleaning the variable resistor contacts yourself. Search the Internet for “multifunction switch repair.” If you can’t disassemble the MFS or the cleaning doesn’t work, replace the entire unit and reinstall the covers.
Taking Off the Steering Column Cover
Remove the screws from the bottom half of the steering column cover and note the length, thread style and location of each screw. They have to go back in the same place. Disengage the plastic snap clips and separate the two halves of the steering column cover.
Check the Resistance
Connect a multimeter to the wiper contacts on the switch to check the resistance readings. Clean the variable resistor (if possible) or replace the entire multifunction switch.