Look on the driver's side inner fender, or, ... It will be on the same side as the battery. Follow the red positive battery cable to it.
I know this doesn't match your description, but it's worth mentioning. If you get one loud clunk from it when you turn the ignition switch to "crank", look for a loose large nut on one of the two fat cables. That's a real common problem. Just tighten the nuts, but don't let the wrench touch anything else. Big bad sparks will result.
If there is one single small plug-in wire, the solenoid can test good and be defective. There are actually two coils of wire inside. Both are needed to engage the solenoid, but only one is needed to hold it engaged. One coil is shorted out once the heavy electrical contact engages. That makes its current available to the starter motor. It can be just the little extra current needed to crank the engine on a real cold day. Because there are two coils, one can be burned open and the other one will cause the unit to test good with an ohm meter. Only one working coil usually doesn't make a big enough magnetic field to move the plunger to engage the contact. Sometimes banging on it will make it engage while a helper is trying to crank the engine.
Also check that the solenoid is mounted to the body securely and the bolts aren't rusty. That mounting plate is the other end of the coils.
You can also unplug that small wire, (it's usually red with a blue stripe), and use a small jumper wire from the positive terminal of the battery to the small solenoid terminal. If that makes it click and crank the engine, suspect first a problem with the neutral safety switch, next, a corroded pin in an electrical connector, and finally, check the ignition switch.
Friday, March 19th, 2010 AT 8:44 PM