What would cause my car alarm to go off for no reason and my horn to just come for no reason also. and my cig lighters and power plugs chargers not to work. I had to pull fuse to stop them.

make sure that the lighter socket actually has power

check fuse for cig lighter i believe (for whatever reason) GM tied the radio cig lighter and obd II fuse together

The radio and lighter are on the same fuse. You'll have to find the fuse. On most cars the fuse box is under the dash to the left of the driver.

Yup, changing the fuses (or a fuse, for that matter) might work. That sounds like the effect a blown fuse would have. I'd also replace the phone charger, on general principle.

a defective outlet

this is the cigar lighter receptacle causing the problem, take my word on this.

The fuse should be beside the accellerator pedal behind a black cover. Should be a yellow 20amp in the middle row, at the end, closest to the front of the car.

You need to replace the lighter socket. Both of my 1988 S10's had the same problem after a few years of using my cell phone battery charger in the lighter plug. I replaced it 10 years ago and it has been fine ever since. Something in the original socket wears out and causes it to short out when something is plugged in. Good luck!

The Cigarette lighter is run off of a 20A fuse located in the engine compartment just behind the battery. The fuse map will say P-Out and is in position #14. Hope that helps.

check relays. horn runs on its own relay