Recently I installed a PA System in my 2003 MCS just for fun cause my buddy had it lying around his house. I wired it straight to the battery because I wanted to be able to use it even if the car is off. About 2 weeks again, I went out to my car and my battery was complete dead. Wouldn't even accept a charge. So I got a new battery, put it in and yesterday, I go to leave and it's dead, won't even try to start. Just a click and everything's off. Tried to charge it over night, went out there this morning and nothing. So I had another battery, put that in and it's starting fine. I unplugged the connections from the PA to see if maybe it could be draining it. The thing is, the PA Amp box has a on/off switch which I use and make sure it's off every time. How else could the battery be draining? Even if it's off could it be sending power? I connected straight negative and the positive. Should I have connected it to a ground instead of the negative terminal? Please help! I can't afford another battery! Also, would the check engine light come on if I need a new alternator? If so, where can I get one? Hard to replace?

 

and it's toast with the PA, it's the PA system. I'm guessing the switch isn't turning everything off!

Yes, a toast alternator will show the bat light.

Now you know why the PA system was just lying around! You've got a couple of choices: Wire it into a switched fuse so that it's not getting any power when the car is off. Wire in a relay to do the same thing (FES makes a high current relay module, Matt says with a shameless plug). Ditch the PA system.

Anyway, I'm guessing the batteries aren't really dead, but just need a really good and long charge. I may be wrong here though.

Matt

 

I'm assuming since you did not mention anything else that your not hearing any noise such as power steering pump staying on after you shut down as this will also drain your battery. Your better off ditching the PA system or as mentioned going to the hot or not fuse forum and getting power from a switched circuit or such. Hooking directly to the battery is not always the best way as you have little to no protection should something short out

 

Wow, you guys are fast! lol

Here's the deal, Nothing else seems to be on after the car is off. But I am not sure it is the PA since I have done a lot of electrical stuff recently. Bought new headlights which required me to wire the Halo's in with the parking lights (shouldn't make a difference), replaced all my lights (footwell, dome) with LEDs (which also should make a difference, if anything it should help) removed the rear window wiper and taped off the plug. Don't think that any of these could do something like this. The PA is on an inline fuse. But what get's me is I tried to charge the battery ALL night with it still in the car and nothing this morning. But maybe something was drawing power while trying to charge it and nothing doing anything at all. I put a different battery in and unplugged the PA to see if this will work while the other battery is upstairs on the charger. Also, this only seems to happen when I don't drive the car for a day or so. Maybe I can wire it into something that only turns on with the ignition? That was there is no possible way for it to draw power? If that even is the problem. Also, I don't think it's the alternator because it idles fine, power steering working fine at idle as well. And I jump started it one time on the stock battery, drove for about 1-2 hours, got home and the battery was still dead wouldn't accept a charge so that time I new it was the battery but the alternator was letting the car run fine.

 

Do a forum search for hot or not great source of information when it comes to switched vice not switched power circuits.

 

Have you done a load test on your alt? make sure it is actually charging the battery?

 

How do I do that?

 

You should go to the local autoparts store in your area, they can do a load test on the Alt and see what is going on

 

Okay! Went to AutoZone and they did a test, alternator is fine! I am going to keep the PA unplugged and see if that is what's doing this. If it is, I can just wire a switch into it and that will fix the problem right?

 

I would think you have a pretty big current draw if the battery keeps going dead., try the PA and see what happens, if its not then you have to start looking at other things that could be drawing current.
Good luck, let us know how it goes

 

I am going to start with this. A couple of days and I will check it. Thanks for all the help everyone! I really appreciate it!

 

This is what makes NAM a great resource. With over 60,000 members someone has tried or experienced what your going thru. Be it good or bad all you have to do is look and or ask and the answer is there.

 

I agree! I have been on many different forums and this one is by far the most helpful and everyone is friendly and not always downing people on what they do to their cars!