I sold my friend my 1991 Eldo, it has 240k miles on it and when he went to start it up it wouldn't turn over, but rather you would hear a faint ticking. My first thought was the starter, but after letting it sit, it started up with no problems. This has happened a couple of time now. My next thought was the battery cables, b/c i went to the voltage screen and it was reading 12.8- 13.0 volts. Is it possible the starter is not not getting enough power from the battery due to the battery cable? I had something similar on my Concorde. The battery light came on, took it to the dealer they replaced the alternator (spent all my pretty pennies on that), but the light still came on. Took it back they replaced the battery cables and all was fine. Any help would be very appreciated.
If it is the battery cables then the negative one is very easy to diagnose. Just hook a jumper cable from the negative battery terminal to the chassis/engine ground of the engine to create a redundant ground path, bypassing the negative cable. If the car starts fine then it is the negative cable.
Take the terminals off the battery and look at the positive cable at the terminal. Sometimes the wire itself starts to corrode inside the insulation.... Look at the insulation to see if it is "puffy" at all indication corrosion inside and/or wiggle/bend the wire at the terminal to see if it is brittle/corroded.