Multifunction switch how do i get the big electrical plug back together

Do you know how to test automotive electrical circuits using a DMM - digital multi-meter ?
Principles of Operation
The headlamp switch is supplied power at all times from the smart junction box (SJB). When the headlamps switch is placed in the headlamps ON position, power is routed to the multifunction switch. Depending on the position of the multifunction switch, power is routed through one of two circuits to the SJB. If the multifunction switch is in the high beam position, power is routed through SJB fuse 12 (15A) and then on to the high beam headlamps. If the multifunction switch is in the low beam position, power is routed through SJB fuses 11 (10A) and 15 (10A) to the LH and RH headlamps, respectively. Power to the multifunction switch is available at all times for the flash-to-pass feature.

Is there B+ voltage at fuse's # 11 & 15 with headlamps on an the multifunction switch is in the low beam position ? If not check for B+ voltage at the multifunction switch . Free wiring diagrams here
http://www.bbbind.com/free-tsb Enter your vehicle info. year , make , model an engine . Under system click on lighting then under subsystem click headlamps . Click the search button then the blue link .
Basic Electricity for Service Techs Ohm law Current Flow Opens Shorts
Electric Testing Techniques You Need to Know

Finding a wiring diagram an using a DVOM - digital volt ohm meter an testing the electrical circuit is the proper way to diagnose electrical problems . Looking at the wiring diagram for your vehicle i see it doesn't have a blower motor resistor , it is a blower motor contol processor . Electronically controlled .
HVAC Blower Motor Circuit
GMC Yukon HVAC Blower Motor Won Turn On

Hey Dana,

First off be sure to take off the negative battery cable then the positive. Wait a couple of mins. so your airbags don't deploy. Remove the steering column cover and then the two retaining bolts. Pull the switch out, unplug the connector and withdraw the switch assembly from the steering column. With new switch plug in the electrical connector, place the switch in position and install the screws. Tighten the bolts securely and put the steering column cover back on. Put the battery cables back on.

That sounds like the multifunction switch is the fault. The flasher on this vehicle is part of the hazzard switch. It recieves power for turn flashing from the turn signal switch. It is very common for the turnsignal (multifunction) switch to become worn and supply partial power to the flasher (hazzard switch) when not on which results in this fast clicking without any lights on. To be certian without taking out any tools whatsoever the next time the clicking happens jiggle the turn signal switch and see if it goes away or changes at all. If it does you need the turn signal switch. I'm going to include replacement instructions for that below because I am confident that is what you will need. Please ask if you have any further questions.



Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
Disconnect the negative battery cable.
Disable the supplemental inflatable restraints (SIR).




Remove the tilt lever.
Remove the 3 Torx® head screws from the lower column shroud (3).
Remove the upper column shroud (1) tilting up and unsnapping from the lower column shroud hinges (3).
Remove the lower column shroud (3) from the steering column (2).
Remove the Torx® head screws (1) from the multifunction switch (2).
Object Number: 442014 Size: SH

Disconnect the electrical connectors (3) from the multifunction switch (1).
Remove the multifunction switch (1) from the column (2).
Installation Procedure




Position the multifunction switch (1) on the steering column (2).
Connect the electrical connectors to the multifunction switch (1).


Install the Torx® head screw (1) to the multifunction switch (2).

Tighten
Tighten the screw to 6 N·m (53 lb in).



Install the lower column shrouds (3) to the steering column (2).
Install the upper column shroud (1) to the steering column (2).


Install the Torx® head screws to the lower steering column shroud (3).

Tighten
Tighten the screws to 2 N·m (18 lb in).
Install the tilt lever.
Enable the SIR system.
Connect the negative battery cable.
Ensure that the multifunction switch functions properly.

Mike39819.098075081


Hope helps.

The turn signal flasher for a 2000 Mercury Mystique is located at the top of the steering column on the back of the multifunction switch. It plugs into terminals 31, 49 and 49A shown in the picture below.

You can get to it by removing the screws and taking the steering column shroud off.

The place to buy one would be at an auto parts store. (Just pick one...they should all have it.)

It is the switch on your steering column that runs the turn signals hazers high and low beams and wipers. The big lever that you use to turn your turn signals on is part of the switch and is replaced when you replace the multifunction switch. It is the whole thing.

Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF , unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.
2. Remove the steering column trim covers.
3. Remove the retaining screws from the multifunction switch.
   
   

   Fig. Remove the multifunction switch (2) from the steering column
   

4. Remove the multifunction switch from the steering column.
5. Disconnect the electrical connectors from the multifunction switch.

To install:

1. Connect the electrical connectors to the multifunction switch.
2. Install the multifunction switch to the steering column while depressing the spring loaded horn pin.
   NOTE Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
   
3. Install the retaining screws to the multifunction switch and tighten the screws to 36 lb inches (4 Nm).
4. Install the steering column trim covers.
5. Connect the negative battery cable.
6. Ensure that the multifunction switch functions properly.

The switch powers up the coil in the relay thus closing the contact points for your lights to work. Recheck switch for positive shut off and check relay for points sticking together, allowing lights run full time.

Multifunction Switch -I suspect this switch or the connection at the harness is bad or contaminated. Removal & Installation To Remove:

1. Disconnect and isolate the negative battery cable.
2. Remove the upper and lower steering column shrouds.
3. Disconnect wire connector from the back of the multifunction switch.
4. Remove screws holding multi-function switch to steering column adapter collar.
5. Remove the multi-function switch.

To Install:

1. Position the switch on to the steering column and install the mounting screws.
2. Connect the electrical connectors to the switch.
3. Install the upper and lower steering column shrouds.
4. Connect the negative battery cable.

Does the truck have daytime driving lights ? Sounds like a short , maybe the switch inside the steering column . Turn signal , wiper , headlamp dimmer ,or multifuction switch . Without testing this is just a guess . Find a wiring diagram at http://www.bbbind.com/free_tsb.html there free , get yourself a DVOM - digital volt ohm meter an test the B+ volt into an out of the switch . moving dimmer from low to high an turning on the turn signals etc.... Suggest you watch a few videos on youtube for automotive electrical testing , how to use a wiring diagram etc.... disconnect circuits at the mutifunction switch .

Measure the resistance between multifunction switch C202a pin 44, circuit 44 (LB), harness side, and electronic flasher connector pin 1, circuit 44 (LB), harness side; and between multifunction switch C202a pin 44, circuit 44 (LB), harness side, and ground.

• Is the resistance less than 5 ohms between the multifunction switch and the electronic flasher, and greater than 10,000 ohms between the multifunction switch and ground?

Carry out the multifunction switch component test; Refer to Wiring Diagrams Cell 149 for schematic and connector information.
.

• Is the multifunction switch OK?

Yes INSTALL a new electronic flasher. TEST the system for normal operation.

No INSTALL a new multifunction switch; REFER to Section 211-05 . TEST the system for normal operation.
Testing the electrical circuits of all the system not functioning properly is how you go about finding the problem .

1. Visually inspect the following for obvious signs of mechanical and electrical damage.
   
   Visual Inspection Chart Mechanical Electrical
   • Headlamp switch
   • Multifunction switch
   • Battery junction box (BJB) fuse 3 (30A)
   • Central junction box (CJB) fuse:
     • 5 (15A)
     • 16 (20A)
     • 26 (10A)
     • 28 (10A)
   • Wiring harness
   • Loose or corroded connections
   • Headlamp relay (if equipped)
   • DRL relay No. 2 (if equipped)
   • DRL jumper (if equipped)
   • RAP module (if equipped)
   • Central security module (if equipped)
   • Light sensor amplifier (if equipped)
   • Headlamp bulb

1. If the concern is not visually evident, determine the symptom and proceed to the Symptom Chart.

Symptom Chart
NOTE: Refer to the Wiring Diagrams for connector numbers stated in the pinpoint test.
Symptom Chart Condition Possible Sources Action

• Both headlamps are inoperative

• Battery junction box (BJB) fuse 3 (30A).
• Headlamp switch.
• Circuitry.
• Multifunction switch.

• GO to Pinpoint Test A .

• The low beams are inoperative

• Central junction box (CJB).
• Circuitry.

• GO to Pinpoint Test B .

• The high beams are inoperative

• CJB fuse 16 (20A).
• Circuitry.
• CJB.
• Multifunction switch.

• GO to Pinpoint Test C .

• One low beam headlamp is inoperative

• CJB fuses:
  • 28 (10A) (LH).
  • 26 (10A) (RH).
• Headlamp bulb.
• Circuitry.

• GO to Pinpoint Test D .

• One high beam headlamp is inoperative

• Headlamp bulb.
• Circuitry.

• GO to Pinpoint Test E .

• The headlamps are on continuously

• Headlamp switch.
• Circuitry.
• Multifunction switch.
• Daytime running lamp (DRL) relay No. 2 (if equipped).
• DRL jumper (if equipped).
• Headlamp relay (if equipped).
• Remote anti-theft personality (RAP) module (if equipped).
• Central security module (if equipped)
• Light sensor amplifier (if equipped).

• GO to Pinpoint Test F .

• The high and low beam headlamp is inoperative on one side

• Circuitry.

• REPAIR circuit 57 (BK). TEST the system for normal operation.

• The flash-to-pass feature is inoperative

• Multifunction switch.

• CHECK circuit 196 (DB/OG) for an open. REPAIR if necessary. If OK, INSTALL a new multifunction switch; REFER to Section 211-05 . TEST the system for normal operation.