I bought my Mystique Mercury a year ago and it is now happening that, if I leave the stereo turned on, the engine does not start. The switch opens, but the starter does not respond. It is only after trying many times that I can finally start driving. Can anyone guide me please? I really do not know what might be happening. I thought about changing the battery, but I do not know if it is the best option.
I personally believe the problem must be in the ignition switch. If the alternator was not charging the battery, the engine would never start. In order to check if they are failing, do the following: with a digital voltage meter measure the battery terminals which, at rest, should have a voltage of around 11.95-12 volts; then start the engine and leave it at idle speed, measure the voltage again and it should be around 13.43 volts. If the voltages are lower than those values, the alternator is not working and depletes the battery. Hope it helps.