My Ford Taurus 2005 clicks but won't turn over when I try to start the engine. Headlights and dash lights flash or come on very dim when key is in ignition. Is this a bad alternator?

I would press the unlock button on the remote to be sure your alarm is fully disengaged.If it still won't start, Then, try fully charging your battery out of the veh. overnight. I would also clean all the corrosion off the contacts. If your positive cable is a 2 piece at the battery and fuse box under hood, also check those connections. Check the ground to chassis and engine block wire as well.Replace battery when fully charged and if veh. starts, turn on all your electronics in the vehicle. Lights, defrost, heater, etc. Watch for things to dim. If it looks like battery is being overdrawn, have a load test done on your battery, out of the car at a parts store (should be a freebie). Then a charging system check done at a reputable repair shop. It is always best to start this whole procedure with a fully charged battery, and if the battery will not take a full charge, it may be the issue.Good luck.

Thanks! It was the battery. Looked like the previous owner had bought a junkyard battery.

It turn over but won't start like it ain't get no gas