'87 4kq: headlight dimmer switch/stalk

[Andrew Buc]

As my windshield washers weren't working, I just had my wiper switch (p/n 855
953 519B) replaced. That fixed the washers, but I have a new problem. When I
first took the car out at night after getting it back from my mechanic, I tried
to turn on the high beams. On pulling the turn signal stalk towards me, I didn't
hear the expected click, and the headlights stayed on low beam. I tried a few
more times, w/the same results, so I had my mechanic (who makes house calls)
come over yesterday.

Once he got the steering wheel off, he found that if he directly worked the
dimmer switch (part of the wiper switch assembly) with his fingers, the lights
would switch between high and low beam. With everything back together and
pulling the stalk, it was no go. This was true with both the old and new wiper
switches. He did a brief show-and-tell, so I've seen all this in action. We
can't see anything on the stalk that looks as if it should engage the dimmer
switch and pull it back, but it also doesn't look as if anything has broken off.
Any suggestions? If it turns out that I'm in the market for a new turn-signal
stalk, does anyone have a part #? TIA