Security alarm, auto unlock, parking lights, door ajar, oh my!

[Weekend]

The first thing I noticed was a door ajar signal while I was driving... sometimes a stutter of locking as if the car was just placed into drive and the auto locks were engaging. The next thing I noticed was the alarm going off every now and then... and now it's consistent -- almost every night and/or in the parking lot when I am shopping.

To me all of those pointed to a bad door ajar light... but recently I've seen two new behaviors that have me stumped:

1) If I take the key out of the ignition, open the door, and then press lock... the doors automatically unlock again as if the explorer thinks the keys are still in the ignition
2) If I have auto headlamps turned on, I notice my parking lights cycling on and off

Should I keep troubleshooting the door ajar switch, or does this sound like some kind of control module going bonkers?

 

[Luke G.]

I had the same exact problem with my 2002 Explorer. I troubleshooted which door ajar switch was faulty. 8/10 times its the driver side door. For the new behaviors, it sounds like its related to the door ajar switch.

 

[LMHmedchem]

Should I keep troubleshooting the door ajar switch, or does this sound like some kind of control module going bonkers?

I always start with anything I know needs to be fixed. You know the door ajar switch is a problem, so fix that since you know you need to do that anyway and see if it helps with anything else.

There are lots of things that are affected by broken wires in the door boot, so that is somewhere else to look if fixing the switch doesn't clear up the rest.

LMHmedchem

 

[toypaseo]

Unsure if it is the same deal as in my 96, but I had issues with the factory alarm going off at random times. I replaced the battery under the hood, and that solved my problem.

 

[WildBill798]

My '02 is also having some of the same issues, door chimes, door locks etc. Sometimes just barely touching the brake pedal seems to do it. But when I get about a half mile down the road, it never does it again. ... unless I stop and turn it off.

 

[Lauri salow]

My '02 is also having some of the same issues, door chimes, door locks etc. Sometimes just barely touching the brake pedal seems to do it. But when I get about a half mile down the road, it never does it again. ... unless I stop and turn it off.[/

 

[Lauri salow]

I'm having the same issues with my 03 sport trac plus it happens every time I hit the brakes the locks act up and interior lights come on and buzzer goes off!

 

[Weekend]

As it turns out, I had two problems. The security alarm and the random door lock/unlock problems were fixed with a new door ajar switch.

These:
1) If I take the key out of the ignition, open the door, and then press lock... the doors automatically unlock again as if the explorer thinks the keys are still in the ignition
2) If I have auto headlamps turned on, I notice my parking lights cycling on and off

Went on for a while, but eventually my battery started underperforming. A new battery ended up curing both of those... I assumed it was a control module going bad, but I don't often think about a control model being flaky because it wasn't getting enough voltage -- but this seems to be the case here.

 

[Lauri salow]

As it turns out, I had two problems. The security alarm and the random door lock/unlock problems were fixed with a new door ajar switch.

These:
1) If I take the key out of the ignition, open the door, and then press lock... the doors automatically unlock again as if the explorer thinks the keys are still in the ignition
2) If I have auto headlamps turned on, I notice my parking lights cycling on and off

Went on for a while, but eventually my battery started underperforming. A new battery ended up curing both of those... I assumed it was a control module going bad, but I don't often think about a control model being flaky because it wasn't getting enough voltage -- but this seems to be the case here.

I am at my wits end with this it's like looking for a needle in a haystack

 

[swshawaii]

As mentioned by toypaseo and Weekend above, weak or faulty batteries are KNOWN to cause MANY different electrical and lighting issues and gremlins with Explorers including ST's. First thing to do is call around and find an auto parts store that can LOAD TEST test the battery
as a free service. Weak battery symptoms aren't just limited to slow cranking, no start, or dim lighting. I've even seen dash lights on ST's going berserk due to a faulty battery. Test the battery and report back.

Hello my name is Lauri, I hope you can help me! When I put on the brakes of my 2003 explorer sport trac it unlocks and locks, interior lights come on and off, door ajar light blinks on and off and a buzzer comes on and off! Can someone help me

 

[Lauri salow]

As mentioned by toypaseo and Weekend above, weak or faulty batteries are KNOWN to cause MANY different electrical and lighting issues and gremlins with Explorers including ST's. First thing to do is call around and find an auto parts store that can LOAD TEST test the battery
as a free service. Weak battery symptoms aren't just limited to slow cranking, no start, or dim lighting. I've even seen dash lights on ST's going berserk due to a faulty battery. Test the battery and report back.

I have a new optima yellow top battery

 

[Lauri salow]

I have a new optima yellow top battery in my sport trac

 

[Lauri salow]

As mentioned by toypaseo and Weekend above, weak or faulty batteries are KNOWN to cause MANY different electrical and lighting issues and gremlins with Explorers including ST's. First thing to do is call around and find an auto parts store that can LOAD TEST test the battery
as a free service. Weak battery symptoms aren't just limited to slow cranking, no start, or dim lighting. I've even seen dash lights on ST's going berserk due to a faulty battery. Test the battery and report back.

I have a new yellow top optima battery

 

[07gtman]

i have fixed my door ajar light with wd40 spray a liberal amount on the door latch on the edge of the door open and close it several times you may have to figure out which door it is.. my 02 mountaineer does this every winter sometimes its a front door sometimes a rear i just do all of them now..

 

[Lauri salow]

i have fixed my door ajar light with wd40 spray a liberal amount on the door latch on the edge of the door open and close it several times you may have to figure out which door it is.. my 02 mountaineer does this every winter sometimes its a front door sometimes a rear i just do all of them now..

Thank you

 

[07gtman]

As mentioned by toypaseo and Weekend above, weak or faulty batteries are KNOWN to cause MANY different electrical and lighting issues and gremlins with Explorers including ST's. First thing to do is call around and find an auto parts store that can LOAD TEST test the battery
as a free service. Weak battery symptoms aren't just limited to slow cranking, no start, or dim lighting. I've even seen dash lights on ST's going berserk due to a faulty battery. Test the battery and report back.

if the wd40 does not work swshawaii is right about the gremlins some new batteries arent allways good batteries..