Well guys I'm new here and I'm sure glad I found you. I have an 89' honda civic Si. A few weeks ago I started having a problem with the battery holding a charge. About a year ago I seemed to have the same problem and the ignition switch was the culprit I changed the ignition switch and everything was back to normal, until now. Brought the battery in and had it tested, it works fine. The battery is only three months old. No dead cells. Went back and had the alternator tested, while still in the engine and it's fine. If I disconnect the battery, it will hold a charge, if I connect it, I can start the car and drive it. But if I shut the car off for any length of time it won't start, the battery will be dead. If I get it jumped, it will start right up......Ignition coil maybe? Could it be my igtion switch again? What exactly is fuse 15 under the dash? Your comments would be much appreciated.

 

Check whether fuse 14 (alternator) under the dash is blown.

If the fuse fine, check for parasitic drain:

http://batterychargerstore.com/what-...tic-drain.html

 

Here's a diagram with all the underhood fuse numbers, and what each fuse serves:


15 is to the cooling fan, and 14 is for the alternator. Check fuse 14, check whether is blown or not getting juice. Also check for parasitic drain like what RonJ said.

 

Thanks guys for the info......I checked the the fuse it seemed to be in good working order. I'll probably replace it just to be sure. I'll see about getting an ammeter and checking amperages.....if you have any other ideas please let me know, thanks guys.