I have the same problem on my late 2007 White polycarbonate. Of the 2 temperature sensors, the one closest to the display originally had 1 "wall" of its base broken off. It was nerve shaking tedious as all get out trying to get that itty-bitty connector to stay in/on a (now) 3-wall base, and without snapping its itty-bitty cables! Hours, bright lighting, magnifying glass, me + every tiny tool I could muster up ... we all gathered in a room with a white floor & little more... in the likelihood that such a tiny piece would fall out of my hand and plummet to the floor AT LEAST a few times (and it did)!
Over time, wall by wall, the sensor base broke down, and this week, it's now officially non-existent. My poor connector is now homeless! And now, due to a liquid spill (my first ever, forever blemishing my lifelong (17-years of computer use) perfect record!), in addition to a cracked case (my 3rd), and 80% of my screws missing, a mag safe power adapter that's held together AND attached to the port with "white" duct tape (to match of course!), a battery that I no longer keep in its battery bay because it doesnt charge, and Chrome that I can't update due to apparent compatibility issues (I've upgraded from Tiger to to Snow Leopard to Lion 10.75), and MS Office that I bought from the Apple Store when I bought my Macbook with LoJack, but now can no longer use (not compatible with Lion *sigh*), plus the never-ending Flash problems, and Chrome's horrific resource-hogging "Pepper Flash" that I can always count on to get my fan roaring ... and now, after a Pepsi Big Gulp blanketed my keyboard top-to-bottom, left side-to-right side, my KB/trackpad are shot, the power button doesn't work/respond and my speaker is toast!! (I do animated video, ebook, smartphone, gps & kids app narration and was mid-project when the accident occurred). *ugh*
SOOOOOO I figured out that I can i gently touch a wire to the (now) empty base that housed the KB connector! Works like a charm! I saw/heard the fan start up and jumped for joy and I'm using it to type this! I haven't figured out how to power it down yet (will touching the wire also take care of that? Any ideas?)
And yet, despite all this (and more), my 2007 White Polycarbonate Macbook 13.3 A1181 keeps going and going and going! <3 It's obviously female!
A big heartfelt thank you to my L<3ve! I owe you a huge debt of gratitude. You have been my saving grace, my rock, my best friend and, again, I just wanna say "Thanks!" for always being there for me! Stay strong! And even though I see a new Macbook on the horizon, I'll just "use" it. You, on the other hand...you were my first and you will always be my baby! Now quiet down that fan a wee bit huh? Muah! xxoo
~Liz R, So Cal