Can disconnected horns cause the theft system problem DIC readout in 1999 eldorado

More then likely the horn relay is stuck closed ,sounding the horns all the time . The horn gets power from the power seats circuit breaker ,no fuse . Relay located in under hood relay center .

A new battery will not correct a theft activation issue. If the system is activated the theft light will blink and the vehivle may start and stall or not start at all. You can try locking/unlocking doors with key fob to see if the system resets. If it doesn't reset, there is a procedure of turning the key to the on position and leaving it there for 15min. Turn key off and then try and start vehicle. This may reset the security system.

LOCKING THE DOORS WITH THE FOB AND THEN UNLOCKING THE DOORS WITH THE FOB WILL RESET THE FACTORY ANTITHEFT SYSTEM.

You can't just disconnect the anti-theft system ! . If the modules on the vehicle don't receive a coded response form the anti-theft system the vehicle will not work , no start ! This coded response is send on the class 2 serial data communication bus to the PCM - engine computer , if it doesn't see it the fuel system , fuel injectors won't be turned on ! an in some cases the engine won't even crank over !
I have read of a way to by pass the system ! If you google GM vats an pass key by pass , you will see how to do it . Don't know if this works or not ! Haven't tried it !

The remote needs to work if the vehicle originally came with the remote from the factory. It gives off a signal to the ring around the ignition switch to deactivate the alarm.

horn button sticking or you have bad horn relay.horn button wire touching ground.

Google this. "passlock relearn procedure"

Go around the car to the passenger side, and insert the rounded door key in the door, then lock and then unlock the door with the key. This should disable the anti-theft system. This also will shut off the horn blowing when the alarm is tripped. This works on all older Cadlillacs. Hope this helps.

your screwed , the starter is under the intake manafold, if mine goes iam junking it , nothing causes it , it just happens,there eldos out there with well over 200 thousand miles on them with the original starter in them then theres eldos with 80 thousand on them that need a starter, its crazy, my 98 got a new radiator alternator speed sensor plugs and wires all this year ,380 dollars for all ,i saved a fortune doing it all my self, but if the starter goes iam done with it. good luck

Alarm Module Reset Procedure
NOTE: This information applies to a Vehicle Theft Security System (VTSS) that was armed when the battery was disconnected and reconnected.
When the armed VTSS senses that the battery has been disconnected and reconnected, it enters its power-up mode. In the power-up mode the alarm system remains armed following a battery failure or disconnect. If the VTSS was armed prior to a battery disconnect or failure, the system will have to be actively or passively disarmed following a battery reconnection.
The power-up mode will also apply if the battery goes dead while the system is armed and battery jump-starting is attempted. The engine no-run feature will prevent the engine from starting until the alarm system has been actively or passively disarmed.
Passive disarming of the Vehicle Theft Security System (VTSS) occurs when the vehicle is unlocked using the key to unlock either front door or the lift gate. Active disarming of the VTSS occurs when the vehicle is unlocked by depressing the Unlock button of the Remote Keyless Entry (RKE) transmitter.
Once the alarm has been activated (horn sounding, lights flashing, and the engine no-run feature), either disarming method will deactivate the alarm.
Depressing the Panic button (if equipped) on the RKE transmitter will also disarm the VTSS, but the horn will sound and the lights will flash for about three minutes as part of the Panic feature. The horn and lights can be stopped by pressing any of the RKE transmitter's buttons or driving the vehicle above 15 mph.