96 intrepid problems

A couple of years ago I started having problems with my intrepid. The gauges wouldn't work and it wouldn't shift out of 1st gear, but you could still drive it. Also, the power windows and windshield wipers still worked. It wasn't too bad as after a couple of minutes of turning the car on and off the gauges would kick in and it would run fine. I took it to Auto Zone where the put it on the computer and said they didn't know what the code meant because it was a dealer code. So I called the dealership, they said that they didn't know what the code meant since it didn't come from their computer. We didn't want to go spend $70 to put it on their computer so our neighbor, a mechanic, and one of his buddies looked at it and told us it was the main computer. Well just a couple of weeks ago, we went to the junk yard and got a comp. My car ran fine for about 2 weeks and it started back on it's same old problems, except now I can't get the lights to come on at all, even after driving it around (which used to solve the problem). We read somewhere that it might be the BCM, so we took it out today, but have not found a place that can test it to see if it's good, or a junk yard that has another one.

Just wondering if anybody has any other ideas on what the problem could be. I love my car, and it runs great when it's working properly.