Okay so because of the winter here I decided to pick up a truck and use that instead of my Mustang. So i havent driven for about 2 weeks because of the weather. But yesterday went to start it up and noticed something wrong. My lights wouldnt turn on and radio wouldnt work but started and ran fine. When I trun the car off it says check charging system and fuel tank empty even though it is full. Checked all fuses everything is okay. Any ideas why it would be doing this and how to fix it?

 

Shaker 500 stereo. Known issue it will drain your battery, it helps to turn it off before shutting off the car.

 

Yeah I have heard of that but my system that I uses is an aftermarket Alpine System. but the car turns over fine and everything starts up quickly too but just no radio and lights work. The computer readout still comes up and when I run that system check shows everything as okay just when I turn it off it says Check Charging System

 

Low voltage tends to wreak havoc with our electronics and we all know the issues with the Motorcraft batteries. Assuming your alternator is ok, throw a good charge on the battery and see if those symptoms disappear. If that's all it is, get a new battery now or by spring. A 3+ year old Motorcraft battery would have me on guard. I expect to replace my g/f's OE battery in her '06 after we get both Stangs out of storage, despite having her battery on a tender.

 

Yeah that is what I am going to do when I get out of work here I also heard that since it hasnt been used alot that sometimes all you have to do is take the battery cables off and reattach them and that should fix them problem too.

 

I started up my mustang yesterday and everything seemed fine lights turned on, radio worked, no check charging system warning. I took it out for a ride around the block and then the radio shut off and interior lights went out. I charged it up seemed fine but did again about 15 mins later. Could there be a short or is possibly the alternator?

 

There's a relay in the upper right hand side (drivers side under the dash) that maintains power when you turn the car off until you open a door. Sounds like relay is going bad. It controls all of the interior electronics. If it's going bad or is bad that would present the issues you are describing.

When you turn the car off and take the key out, before you open a door, listen very carefuly, you'll hear what sounds like two noisey small gears rotating, that's actually the relay. when you open the door it should stop after a second or two.

 

2006 motorcraft batteries sucked. I had all kinds a crazy issues with my 06 escape until they swapped the battery. That would be the first place I would try if the alternator looks good.

 

Dont wanna sound like a douche bag, But the "check charging system" Light will come on, On any vehicle when you shut it off because well the alternator isnt chargin From what your describing sounds like a intermittent open wire. If it was a short you would Fry wires, Or blow fuses. And if the battery was shot, The motor would not crank. And you cannot, cannot tell me other wise. This is were i would jab you my credentials. Boo Yaa. Trying to make this funny btw. But also serious. Hope this helps a little

 

I did check this out and that is what it sounded like so I will look into getting this fixed shortly. Thanks for the help and I will let you know how it goes.