Oh yeah...sunrunner. A solenoid is a remotely operated devise used to allow smaller wires to run bigger wires. Developed basically so that gigantic cables would have to run inside your dash. The solenoid that you are talking about would be the starter solenoid. It is located on the starter of the car. Its job is to put positive electrical current into the starter to turn. It is connected to the positive wire off the battery, and is fed through typically the starter relay which comes directly off the key. You had the right idea...just slightly wrong location...and no they are not always 20 bucks. Sometimes you cannot get them seperately. The fact that the starter managed to turn a couple times tells me that the solenoid is working. Should it or the starter be sticking..then he would get nothing at all.