1999 Jeep Grand Cherokee exterior lights flash for "no" reason


Here’s one I haven’t heard or seen before. I have a 1999 Jeep Grand Cherokee Laredo V8 with a dealer-installed alarm. The alarm operates off the factory keyless remote fob; arming when the doors are locked and of course disarming when the remote unlocks the doors. All of the exterior lights flash and there are corresponding chirps from the alarm when it is either armed or deactivated.



So, the issue. Well, for no apparent reason, all of the car’s lights flash as if the alarm was being armed or deactivated as it sits parked in front of my home. There are no audible chirps (thank god or the neighbors might have “fixed” the problem for me) and the doors do not lock or unlock with each flash.



I have noticed this happen in the evening, with lighting in the far-off distance, but there was no rain. It has also happened around 5 am on a still morning. Sometimes the flashing will go on for a few minutes, with a couple of intermittent sets of flashes. Listening carefully, I have not heard the chirps of any other car’s alarm as my lights flash. The car sits in front of the house all week and is used evenings and weekends. I haven’t noticed this phenomenon during the day or away from the house.



While this is a relatively new issue --I’ve only noticed it in the last couple of months-- the battery has never been drained by the flashing.



My thought initially was there was another car’s alarm with an identical code, but alas no chirps were heard. Then I had the brain wave (just one) that it might be a computer’s wireless router close by, with the flashes occurring as data is transmitted.



So, I was wondering if you thought that was a possibility or there is another electro-mechanical explanation? If not, I don’t think that black electric tape is a viable solution, since this involves the headlights, brake lights and turn signals. While this may date me, should I just learn Morse code and change my license plate to either Kit (of Night Rider fame) or Mother (for my Mother the Car)?



I think the most likely thing causing this is a faulty power connection between the battery and the alarm system somewhere. What you describe usually happens when the battery is reconnected to the car’s electrical system. To prove it try disconnecting the fuse to the alarm system and reconnect it.

You may be able to find the bad connection by tapping lightly on suspected areas using a screwdriver handle. The trouble area may be near the battery or main panel under the hood. The trouble may also be inside the alarm system itself.