Need help. Problems i cant figure out

I just bought a 94 Grand Cherokee Laredo. For some reason the battery will not hold its charge overnight. I found out that it had an aftermarket sercurity system installed. I removed the fuse for that and it still wont hold overnight. I have to disconnect the negative on the battery so it will start in the morning. Also, none of the power windows work and the fuel gage doesnt work. If anyone has any ideas it would be greatly appreciated.

I took the door off and found three broken wires. I put those together and now the windows work. The only problem is when i fixed the windows, the power door locks and radio stopped working. Any ideas?

It sounds to me like you have a dead short in the system, it maybe in the power window or gauge problem, I thought there was a relay for the windows not sure would need to get a wirring diagram, best way I found to track a problem of this kind is to disconnect one fuse let it sit if the battery goes dead put that fuse back in charge the battery and try the next fuse once you figure out what cuircut it is draining the battery you atleast know where to start looking. However dont count the alternator out I had this problem about 20 yrs ago alternator tested fine would charge the battery no problem while running pulled my hair out for weeks trying to figure it out finally replaced the alternator anyway fixed my problem, found out it had a dead short in the alternator itself, so you may try disconnecting the alternator to see if that is the problem.
I wish I knew a better way or could be more helpfull but when it comes to tracking down elec. problems they are tough.
Good Luck

There are quicker methods to locate the circuit that has the draw. 1.You could pull the alternator and take it to an auto store to bench test it for free. 2.Make sure you battery has a full charge. Pull the light under the hood. Use a test light or multimeter. Disconnect the neg cable. Hook the clamp end of the testlight to the neg cable and touch the neg post with the other end. The light should not burn brightly and if it does you have a draw. Pull each fuze and check the light. Once the light dims when a particular fuze is pulled you have found the circuit that has a short. Check your owners manual for the circuits that that fuze services. From there it is a matter of elimination. You could also use a multimeter to measure the amount of ohms being drawn. There is a small amount of draw from the PCM all the time but not enough to kill the battery. I'm not an electrical expert but know some of the basics. There is probably and electrical guru at this site who can illuminate us both. Good luck.

try a new battery, maybe the battery has a bad cell and the key off draw is causing the battery to drain.

Jeeps - have a KEY OFF draw and it puts a constant draw on the battery - thats why after leaving the jeep sit for about a week the battery will be dead. So the first thing I would do is change the battery (NEW) and check the voltage output of the alternator with the jeep idling, you can use a multimeter for this. REPLACE THE BATTERY FIRST