Electrical problems. Car won't start. Battery is good, however, horn won't blow, inside lights won't come on, ignition key turns but nothing happens. Also, speedometer works most of the time but not all the time, Gas gauge does the same. alarm key has new battery but doesn't work. where do I start to look to fix?

I've already replaced the ignition switch, prior to contacting this forum, Under the advise of the professionals at AutoZone and O'reilly's. I believe the car has been involved in a flood although the car fax doesn't list it. It has dirt and sand in unusual places in the engine and undercarrage. I've already replaced the ignition switch, prior to contacting this forum, Under the advise of the professionals at AutoZone and O'reilly's. I believe the car has been involved in a flood although the car fax doesn't list it. It has dirt and sand in unusual places in the engine and undercarrage.

'It's a 97 ford taurus, purchased used has "67500 original miles". Battery cables have been cleaned, checked and the battery has been tested to be good. However, you make it sound as though the battery may not be putting out enough juice, and if that's correct, the voltage could be causing the problems. Is this correct? If so, would that make the fuel guage and the speedometer operate improperly? 'It's a 97 ford taurus, purchased used has "67500 original miles". Battery cables have been cleaned, checked and the battery has been tested to be good. However, you make it sound as though the battery may not be putting out enough juice, and if that's correct, the voltage could be causing the problems. Is this correct? If so, would that make the fuel guage and the speedometer operate improperly?