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2004 Chrysler Pacifica-Problems with Horn, Power Door Locks and Windows, Keyless Entry, and Interior Light

A few weeks ago, my horn starting blowing without me honking it. It would blow for about 30 seconds, then stop, then about a minute later, start the cycle again. This happened even when I turned off the car and restarted it. The only way I could get it to stop was to remove the fuse.

Last night, I went to the gas station and went inside. When I returned to my car, the keyless entry on my ignition key wouldn’t unlock the doors, though it did make the lights inside and out flash, as usual. When I manually unlocked the driver door, I noticed that the interior light on the driver’s door came on but wouldn’t shut off, whether I was driving or had shut off the car. Also, none of my power windows are working, nor do the interior buttons on any of the power locks work. Also, I now can’t open my tailgate.

I did a search online as to what the causes may be. One thing I read said that perhaps the theft deterrent system got tripped somehow, either by removing the fuse for the horn or something else. I would think, though, since so much time has passed since the horn going out and what happened tonight, that those issues wouldn’t be connected, but I’m not sure.

Other than this, the car is driving fine and everything else seems to be working.

What should I look at first? I thought of checking the fuses, but I can’t find my fuse puller and so will get one in the morning.

Thank you in advance for your help.

First thing I’d check is the condition of the battery and charging system. Low voltage can mess with modules. Then I’d check power and ground integrity at body module. Then check body module connectors and wiring. Then body module itself.

If you have a second set of keys/fob, try using them. If the problem goes away it’s your fob. Check it’s battery.

All the circuits that are giving you problems are controlled thru the totally Integrated Power Module.


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A good well-charged battery with secure connections is always the starting point for diagnosing electrical problems. The symptom points to a problem with the antitheft system - a switch, connector, wire, ground, its control unit. Is it a factory-installed unit? If so, is a good place to go for questions about Chrysler products, I have found. If not, a local installer may best for diagnosis and repair. Good luck and please let us know.

Sound like the drivers door control module has locked up, this can be caused by electrostatic discharge though the interior door handle. First step is to perform a hard reset by disconnecting and reconnecting the drivers door master switch and check if the windows, door locks and mirrors are operating.

I think the advice that @Tester gave is the key to solving your issue. Those modules don’t seem to have a good reliability record.

Check battery voltage (a) at rest, before stating car in the morning, and then (b) voltage once running and charging.
With Chrysler products, low battery voltage can cause many strange problems.