99 Civic: Key ingnition/door open alarm question

I have a 1999 Honda DX sedan with 73,000 miles. It's been a very reliable car for me, however over the last few months I've encountered a problem that is more of an annoyance than anything, but now the problem
is constant and extremely annoying.
Normally, when one leaves the key in the ignition and gets out of the driver's seat and alarm will beep. I assume there's a sensor of some kind under the seat that attempts to warn the driver of the possibility of locking the keys in the car. I noticed the problem first when I took the keys out of the ignition and exited the car, the alarm still beeped. Close the door, alarms goes off, but the whole thing was random and intermittent. Now, it beeps even when I open the car door before I get in! I can't leave my driver side door open to clean the interior without constant beeping even with the key safely out of the ignition. Could this be a problem with the ignition keyhole or a sensor of some kind or both? What might I be looking at in terms of repair? I looked for a fuse to pull that might temporarily solve the problem, but wasn't sure which one. Any ideas would be greatly appreciated.
mb
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mb wrote:

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It's time to lube your locks anyhow. :-)
Somebody may have used the wrong lube and gummed it all up. Get a small blue aerosol can of LockEase and hose all five locks with the special slim tube. Massage the key around, especially in the ignition lock and see if it loosens up the problem. It's MESSY so wipe the key with a tissue the first few times. Have you checked the function of your door switch (and interior light) as well?
'Curly'
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A warning - although I love Lock-ease it will make a lock that has been WD-40'd worse, sometimes to the extent that the key will require a major struggle to get it out. Apparently the kerosene (or whatever the carrier is) reacts badly with the gum WD-40 leaves behind. If that happens, the only solution I've found is to spray it with WD-40 again. Even soaking in parts dip won't clean the residue out.
Mike
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says...

Thanks. I'll give Lock Ease a shot. As far as checking the door switch, is it a simple matter of seeing whether or not the interior light comes on when you open the door? If that test fails, is it something a novice can easily repair?
mb
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