Mitsubishi Repair: 95 GT 3000, gt 3000, little cars

Question
My grandson's GT 3000 has been having electrical problems for 5 months.  After sitting for a few days at college, the battery is dead.  Car was taken to dealership and after running numerous tests and finding nothing wrong, the battery was replaced.  Car was left outside for a week and again the battery was dead.  Took car to a local mechanic and after running several tests, he said the new battery was faulty.  Put in a new battery and let car set outside for a week in zero weather.  Car started at end of week.  Took car back to college and after the second night sitting in parking lot, battery dead.  Any ideas as to what may be causing this peculiar behavior.

Answer
Larry: My guess is that there is someplace in the wiring a break, when sitting outside, water, you know like you get on your windows in the early morning, even when it has not rained. Just a bit is all you need, you know how water and power mix, water works well for it, so if there is a small break in a wire someplace, enough for some water to reach it and maybe it touches the body, enough to pull just enough to kill the battery. I would say your grandson will have to get a repair manual for his car, most parts stores sell them cost around $20.00 and a voltmeter. He will have to start with the battery and work himself around the car till he should be able to find where the volts are off. I don't think the dealership or the shop would work to hard at finding the problem. It is easier to just say the battery is bad so replace it. Which it is not the battery, another thought is that there is try putting a cover of some kind over the car as to see if the battery would still be dead in the morning. If it isn't then it is due to just the air with a bit of water in it. Sometimes these little cars have odd things to them and it does take a lot of work to find the problem. Another thought is how old is the cables on the battery? We always start with the easy things then work out. I wonder what kind of tests the dealership really did do on the car. Sorry but a lot of dealerships these days are not all that great at doing the tests they should. If you get a repair manual for this car, it would have wiring diagrams in it too. There is one another thought it might be a bad relay. In that you should check the relays in his car. They are in those black boxes in with the engine department, when standing in front of the car with the hood open, look to the driver's side of the car, there should be one black box and then two more by the battery. In them are relays and large fuses. One of these might be the problem. It could be also where the large group of wires comes from the engine department into the steering column of the car. Wish I could help you more. I hope one of these helps. God bless: Linda