I have a 2000 Chrysler 300M. The factory car alarm has started going off for no apparent reason. I can shut it off with the key fob, but after a short time (within 1-5 mins.), the alarm goes off again. If I leave the car unlocked with the key fob, no issues. If I lock the car with the key fob, starts doing it again. Any ideas???

 

Try replacing the fuse

 

Disconnect the battery cable and touch one to the other for about 10 seconds. this will reset everything. and the fuse is fine.lol

 

Well after doing some more research, I was led to believe that the batteries in the key fob were low and that was what was causing my problem. So I changed the batteries. Problem stopped, or so I thought. But I decided to go ahead and get a new key fob since the one I had was old and faded. Got the new one and got it all programmed. Everything seemed to be fine. I needed to retrieve something from my trunk, so I popped the trunk from the key fob, got what I needed, shut the trunk. A few seconds later, alarm starts going off. Reset the alarm and tried again, same result, alarm would go off after opening the trunk and closing it. Also tried the same thing with the old key fob. Same result. Any ideas where to start looking now???

 

Well after doing some more research and investigating I was able to find the problem. The problem was a broken wire and a cracked wire in the wire harness that is attached to the trunk lid. One wire, the outside of the wire was cracked and exposing the wire underneath and another one was completely broken in half. Fixed both with a couple of butt splices and no more problem. Don't understand how the wires got that way in the first place. Wires were wrapped in tape and also inside a fabric type of loom protector. They were not pinched in my opinion, but the outside of the wires appeared to be cracking and splitting. Like they've been exposed to the elements/sun.