Weird problem happened the other day

[LLCoolLS]

I drove home from work one day and decided that I want to finish my coffee and smoke before going inside the house. I shut off the engine and finished up (took maybe 4-5 minutes). I realized that I had to fix my crappy parking job so I turned the key to start it up again. It just started turning over very slowly and would not start. Looks like I drained the battery. Odd because it's a fairly new battery with 920CCA. With the key in the run position, I hit the "status" button to see if a fault was found with the charging system. It still read "Charging System OK" Fine. So I boosted it and put it in my garage. The only memory I lost was my trip ODO.

After parking it and getting out, I noticed that the little box behind the rear view mirror (I think it's the compass and daylight sensor) had a yellow led that was flashing (maybe once every 1-2 seconds), visible from the front of the windshield. I have no Idea what this means and why my car wouldn't start.

I swapped the battery with a spare Optima battery I had lying around, and had the MotorCraft battery tested. It was fine. I'm gonna put this battery back because my Optima battery only has 870CCA.

The flashing yellow light stopped after swapping the battery.

Any ideas as what weird things are happening to my car?

It's an 02 LS8

 

[wallyj]

I drove home from work one day and decided that I want to finish my coffee and smoke before going inside the house. I shut off the engine and finished up (took maybe 4-5 minutes). I realized that I had to fix my crappy parking job so I turned the key to start it up again. It just started turning over very slowly and would not start. Looks like I drained the battery. Odd because it's a fairly new battery with 920CCA. With the key in the run position, I hit the "status" button to see if a fault was found with the charging system. It still read "Charging System OK" Fine. So I boosted it and put it in my garage. The only memory I lost was my trip ODO.

After parking it and getting out, I noticed that the little box behind the rear view mirror (I think it's the compass and daylight sensor) had a yellow led that was flashing (maybe once every 1-2 seconds), visible from the front of the windshield. I have no Idea what this means and why my car wouldn't start.

I swapped the battery with a spare Optima battery I had lying around, and had the MotorCraft battery tested. It was fine. I'm gonna put this battery back because my Optima battery only has 870CCA.

The flashing yellow light stopped after swapping the battery.

Any ideas as what weird things are happening to my car?

It's an 02 LS8

I am having the same problem except for the lights flashing. I try to start it sometimes and it feels like the battery is dead. I try to restart it again and it starts right up. Let me know if you find out anything please.

 

[eastcoastLS]

the yellow flashing light behind the rearview only flashes when the rain sensing wipers are on.

 

[LLCoolLS]

the yellow flashing light behind the rearview only flashes when the rain sensing wipers are on.

Well that answers my one question! I kinda feel like a doofus now, but it's better that I know that I'm a doofus. Thanks!

The starting problem hasn't happened since, but I'm still trying to figure out what happened.

 

[scjmc]

Once abour 18 months ago mine randomally would not start (like it had a bad battery). On the second try it was fine. I still have the same battery.

 

[pbslmo]

Mine did that also, stupidly bought a new battery, but it turned out to be a starter relay going bad. it is located in the fuse block in the engine compartmetn.