Security horn blows when jumping the battery.

[bongo042]

I'm trying to jump my 03 Pathfinder, I let it sit too long, I should've disco'd the battery. Anyhoo the very second I connect the powered leads from my jumper cables, I'm guessing the security system activates and the horn starts blowing in pulses. Tried deactivating with the key fob and that doesnt do anything, maybe that battery is bad as well. Tried turning ignition on/off four times and that didnt work. So I disconnected the horn so I wont bother the neighbors, and there is a separate horn for the security system that blows and I cannot find!

Can anyone offer advice how I turn off the sec. systerm and jump my battery without removing it from the car and buying a battery charger to get it charged again?
Thanks, Robb

[macgiver]

Something to try - disconnect neg cable w/car off & keyout , then turn key to acc then Run position, a few hours reverse all that . Turn key off , reconnect neg cable , NOW connect Jumper cables , couple minutes - go start.
NO horn ? Startup like a jumpstart should ? Done WITH your horn reconnected??

[Mike W.]

I think they're wired in parallel, not a separate security horn, but whatever, there is a horn fuse. Remove it and you should be good. The one horn is easy to spot, the other is buried.

When I was having problems with what turned out to be less than perfect connections on the drivers door switch assembly I was going nuts with the horn going off. I could start the car and drive it, but the the horn wouldn't shut off until I pulled the fuse. Or until it timed out but opening the door would set it off again.