Ford Mustang Forum banner

2005 Mustang GT Charging Issues

6276 Views 12 Replies 6 Participants Last post by  AlaskanWookie1
Hi all,

I am new to the site and I am looking for some help with an issue I am having. I have a 2005 Mustang GT with an automatic and a Shaker 500 sound system.

The issue I am having is dealing with the charging system/battery. I never had a problem with it starting until about 1 month ago. The car turns over very slowly and acts like it is not charging. I have no warning lights on in the dash or anything. My charging gauge is working fine as well.

I bought the car used and had the alternator replaced about a year ago along with the battery (Both Motorcraft) under the dealers warranty.

The slow starting problem will go away if I drive the car for long distances without stopping (20 or 30+ miles at highway speed) but if I am sitting in stop and go traffic or only drive the car for 15 or 20 min the problem will come back. I just got back from a 2000+ mile trip and had no problems, but as soon as I went from my house to work and back (6 miles) the slow starting problem came right back.

I had Ford test the battery and they said it was fine. The battery voltage read 12.6v.

Has anyone had this problem or know of someone who did? If so, do you know how to fix it?
1 - 1 of 13 Posts
More than likely your problem is with the Shaker 500 stereo. You did state that you pulled radio fuse and it helped. If you search these forums and the web you'll see all kinds of problems. We had 05 GT with Shaker 1000 and we had battery problems to. There is a relay internal in radio that doesn't turn all the way off and allows the amps to stay on and drain the battery. Most people say to turn radio off before turning car off. Others say eject all CD's (not sure why?) then turn off radio, then car.

As far as your battery posts... Go to autoparts store and get small packet of dielectric grease for batteries. After you clean them you can coat both battery and cable terminals. This will help with corrision.

You can check to make sure the alternator is charging by using a multimeter as the car is idling you can check voltage at battery terminals. It should be 13v or higher.
See less See more
1 - 1 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.