How to Fix Intermittent-Wiper and Turn Signal Problems on the Multifunction Switch

Tackle repairs to this complicated lever with a shop manual and a digital multimeter.

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Introduction

Turn signals and intermittent wiper controls are the most common failures on the multifunction switch in late-model cars. Save money by doing the repair yourself—it's not as complicated as it looks.

Tools Required

  • Digital multimeter
  • Shop manual
  • Torx-head screwdriver

Remove the Multifunction Switch

Once known as a turn signal or blinker switch, this 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:

  1. A broken turn signal “canceling” mechanism that won’t shut off the “blinkers” after a turn,
  2. 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.

Locating Your Vehicles Multifunction Switch

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).

Car maintenance seems daunting at first, but start small and work up the car repair ladder. Here are 100 car repair tasks and maintenance you can do yourself.

Project step-by-step (4)

Step 1

Take Off the Cover

Turn Signal Problems on the Multifunction Switch intermittent wipersFamily Handyman

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.

Keep track of the screws:

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 to the same place. Disengage the plastic snap clips and separate the two halves of the steering column cover.

Step 2

All About the Multifunction Switch

multifunction switchFamily Handyman

Multifunction switch levers control headlights, flashers, wipers and intermittent windshield washers. 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 (auto parts store or dealer).

If the problem is faulty intermittent wiper operation:

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:

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 neither technique works:

If you can’t disassemble the MFS or the cleaning doesn’t work, replace the entire unit and reinstall the covers.

Step 3

Pull the Switch

pull the Multifunction Switch intermittent wipersFamily Handyman

Remove the switch retaining screws and pull out the switch. Disconnect the electrical connector.

Step 4

Check the Resistance

check the resistance multifunction switch intermittent wipersFamily Handyman

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.

Working on a vehicle can be intimidating for non-mechanic types, but some tasks are very easy to do yourself. The following 13 handy hints will help you complete automotive maintenance and small fixes with ease.