Car will start sometime for days, then not start the next time. only noticed that the battery light stays on a long time

Change your blower motor resistor,it's located next to the blower motor.

http://www.2carpros.com/articles/car-battery-dead-overnight
This may help you find the problem.

I have a 01 Lincoln Continental that wouldnt start. After paying $69 to the repair shop they told me that the alternator and belt are working like they should but the battery wont hold a charge. I took the battery to Sears (6 month old Diehard) and after a day and a half they said the battery is good. Now the car starts each time but the lights(inside and out) all flicker and when you press the gas they flicker more? After about 5 minutes the flickering stops. What could be the problem?

The battery light usually comes on when the alternator is not putting out sufficient voltage equal to or above the battery voltage. Sometimes the alternator can be generating enough voltage to make the light go out but not enough current to recharge the battery properly especially when driving at night with lights etc on. Eventually the battery will not have enough charge left to start the engine. The most common cause of low output is worn brushes but your description tends to suggest that the electronic regulator inside the alternator has an intermittent fault. An auto electrician will be able to diagnose the problem fairly quickly and probably offer to fit an echange unit.

Your transmission torque converter lock up clutch is not unlocking, that kills the engine and is the cause of the OD light flashing.

I would check your main battery terminals to make sure they are not loose. Sometimes, even when you have reconnected them properly they may not be tight enough to make a good electrical connections...I have seen it a million times and I have also been a victim myself :) If you shake them and they swivel at all that may be your problem. Sometimes another way to tell is if you can move them around and the car starts one time, then later that day or sometime down the road the car wont start again this is a sign that the connection is your problem. You should definately try this first, then go from there.

I have same problem either glow plug circuit relay or power signal from main computer faulty. Could also be bad wireing harness they are notorious for this. We put a larger battery (higher cca) in to compinsate for excessive cranking a year later were changing the starter it seems summer comes and we blow it off till its noticable again. If you fix exact problem please let me know what it was if possible. GOOD LUCK and Thanks!

your shifts correctly, as your driving it downshifts and stay stuck at that gear when u stop and try to take off but intell u turn off your car and restart it it shifts correctly intell a few mins later. i am thinking that is a speed sensor (out signal problem) mounted on top of your transmission next to the battery tray, you will see couple of cable linkages next to it ...

start with battery. sometimes older batt. won't hold a charge overnite. disconnect battery and reconnect next day and check. if batt is ok disconnect alternator overnite and connect next day to see if it was problem.

you have something thats staying on with power when you shut the car off,first check all lights glove apartment,underhood,in trunk ,just because ther closed doesnt mean the light is off,check your car at night it might help to see the lights,if not another way is to take a multi meter to the battery and while some holds the meter pull out fuses in your fus box one at a time to see when the meter makes a change,this will help you to narrow down whats staying on and draining the power from the battery,if this helps please give me a fix ya vote