Multi-speed fan switch removal/repair

Courtesy of Tom Gillen with [my comments]

The job is fairly simple, and you can either effect 
a repair as I did or just replace the unit.  Step #10 
identifies the actual problem, which, after examining 
the switch, seems it would be the logical failure 
point for similar units.

1)	With a cloth over a pair of pliers, remove the 
        "knob" from the slide switch.
2)	CAREFULLY pry out the wood trim and the metal 
        backing from around the slide control.  Do 
        this carefully, I said.  The wood trim is very 
        brittle, and, as I've discovered this morning, 
        very expensive to replace.
3)	Remove the foam and plastic insert that covers 
        the switch unit.
4)	The switch is best accessed via removal of the 
        center console (remove ash tray, four screws 
        beneath the ash tray, and one (?) other on the 
        passenger side.....the trim under the glovebox 
        also needs to come out (three screws)).
        [Two screws secure ashtray and two screws 
        secure the bottom of the center console. There 
        are also two screws that secure the top of the
        console that are accessible from the center
        air vents. ('87 16V)]
5)	Pull the console out and down far enough to 
        disconnect the wire harnesses for the slide 
        unit, its light, and the ACC pushbutton unit. 
        This should give you enough room to get the 
        switch out.
6)	Remove two screws through the slide switch 
        opening.  This holds the unit in.
7)	Remove and dismantle unit. Mine actually fell 
        apart upon removal. [To dismantle, gently
        pry the clamshell halves apart with a flat-
        blade screw driver. Be sure to keep the unit 
        flat (top-side up) on a work surface.]
        The two clamshell halves of the switch had 
        separated, and spilled the surprisingly many 
        teeny switch parts.  This was a mess.  
        Although I finally recovered all the parts, it 
        took some time before I was able to understand 
        and reassemble the switch.
8)	I am only an English major, yet I found the 
        switch to be quite a feat of engineering.  Not 
        including the two unit halves, the backing 
        plate/circuitboard, or the two relays that are 
        mounted on it, I had (and you should have)
	-- three small, bat-wing, black rockerarms
	-- two black rubber wheels
	-- a white plastic roller wheel
	-- a white plastic arm that holds the wheel
	-- a small spring that provides tension to the 
           white plastic arm/wheel assembly
	-- three brass clips (the actual electrical 
           switching mechanism)
9)	If your unit didn't fall apart upon removal, 
        operating the slide mechanism should reveal the 
        purpose of all the parts.  It's quite an 
        impressive little system, actually.  The small, 
        black rubber wheels fit beneath the lever and 
        provide a smooth and controlled travel in a 
        molded track.  The three rockerarms fit on three 
        pegs that are keyed to allow only so many 
        degrees of movement.  The brass clips fit between 
        the rockerarms and the unit's backing 
        plate/circuitboard, opening and closing the 
        circuit depending on the movement of the rockers. 
        The spring-loaded, white-plastic roller arm is 
        the lever's extension that rolls beneath the 
        rockerarms and forces them back and forth, which 
        not only opens and closes the circuit for that 
        blower setting, but also provides the firm detent 
        between settings.
10)	The problem is that the small key, molded onto 
	the rearward base of the peg, breaks off, 
	allowing the rockerarm to swing uncontrolled past 
	its intended travel, which allows the spring-
	loaded lever/roller arm to extend up *between* 
	the first peg and the next, thus tightly jamming 
	further travel of the lever.  As the lever/roller 
	arm has a fairly high spring loading, and, in the 
	off position, the first rockerarm is constantly 
	under its pressure (holding that first contact 
	open), it's easy to see why the small molded key 
	either gets ground off or simply shears. 
11)	I had no luck trying to "create" a small key of 
	my own with scrap plastic and/or superglue.
12)	I simply glued the rockerarm in a perfectly level 
        orientation.  This allows the roller arm to 
	travel beneath it, and will prevent it from ever 
	getting stuck there again.  However, this also 
	prevents you from ever using the lowest blower 
	setting. I'll probably replace the unit 
	eventually, since I did tend to use that setting 
	more than the others.
        [I chose a different fix: I drilled a 1/32nd 
	inch hole through both halves of the clamshell 
	and dropped a small cotterpin through the holes 
	to act as a stop for the low speed rockerarm. 
	This returns full functionality to the switch. I 
	used super glue to put the case back together.]
Well, I hope this hasn't been too confusing, and is of 
some help to some of you.

Tom Gillen

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