1995 Honda Accord VSS?

My problem is similar to a couple of others, in that my speedometer doesn't work very often. It will wobble around 20mph, will jump around when applying the brake and it will maraculously work on its own when it is either very rainy or very humid. I've narrowed it down to the vehicle speed sensor, and purchased the part, but no one I've spoken to can figure out where the stupid thing goes.
I've looked at diagrams and both brands of repair manuals to no avail. A new speedo cluster costs almost as much as I paid for the car, and the risk of buying used with the same problem doesn't justify a purchase.
Any other ideas of what it could be?