I took the battery to autozone and it had no juice in it. So, I had it recharged and then tested. It tested as a good battery. Then, I put it back in the car and drove it home from the parking lot that it was stuck in. It started up itself and made it home fine, but it was only two miles away. Now it's parked in the garage. I looked at the OVP relay and it looked okay. I put a different 10 amp fuse in just to be sure. When the engine is off, the battery emits 12.4 volts and when it is in idle it emits 13.8 volts. It still starts up on its own but I notice that the engine sounds really strong then sounds really weak and shakes a lot, then it goes back to being strong, then weak, so on and so on. It does this when driving too. I would stall then get power back. It's been doing that before I had problems with it breaking down. Do you suppose the spark plug wires need to be replaced? I didnt replace them when I did a tune up. I've been trying to get this car ready to sell. If I can get the engine to stop losing power periodically like that while driving, It can pass a test drive and make to the home of whoever buys it. I think I can make it to a mercedes mechanic as long as no accessories are on, but I don't want it to sit there for 2 weeks and to pay the $90/hr. labor charge. That's why I do all the work on it myself, even though I've never worked on cars before I had this one.

thanks