It you are having a problem of ignition fuse blowing (30 AMP) time to time. You should check the fuel pump wires, to do this you have to take the fuel pump out of the tank and check the two brown wires going to the pump. I have worked now on six Mitsubishi Diamante which had the same problem. The two wire rub with each other and lose there insulation at around 70000 miles. After this they start to arch with each other and blow the fuse. All you have to do is cut the wires slide a good quality shrink rap and solder the wire back and make sure that they don't rub with each other. Fuel pump is very easy to take out in this car. Mitsubishi has given an access hole under the back seat. Only tricky part is taking apart fuel line, you will need a tool that you can buy from auto store.
Dealer will charge you $900 to change the fuel pump that you can do yourself in 30 min.
Make sure the Shrink rap you buy is gasoline compatible otherwise it will melt.
To take back seat out pull the two round rings at the each end under the seat. Pull the seat up and slide it out.
PS: Please be careful about the sparks when working near the gas.
Chino Khan