1998 Ford Taurus key in alarm-how to disable. Tried replacing switch but no luck. It runs the battery down. Have to disconnect battery when parked. HELP

Your horn relay may be shorting out, making your horn operate all the time. Have a look at your relays. You might find the horn relay is the same as another relay, If it is, try swapping relays with a known good one, and see if the horn operates normally. If so, get a new relay. Good-Day!

if you have to step on the brake to shift from park, it could be that interlock switch.

You are going to need to replace the ignition switch

It is possible the tumbler in the Igniction switch is out. It is composed of plastic so this can breaK, I just replaced a ign. switch on a 99 Olds with a sim. problem. Good luck

I would say disconnect the battery, and replace the key switch...

the car has shut down (immobilised)you need to replace remote batteries and reset the system...

Before you disable your alarm try this, disconnect the alternator field plug over night, check battery voltage at the battery before you disconnect the plug then disconnect and leave alone over night, make sure you have at least 12 volts when you disconnect the alt.
Recheck battery voltage in the morning before you reconnect the field plug...

I suspect you may have a leaking diode in your alternator's internal regulator, have seen it many times on your model... Certainly worth a try. Let me know how it turns out....

Hi and welcome to FixYa,

To my knowledge, you assumption is correct on most designs. That wire should go to the ignition switch and will be hot when key is in START. However, same wire often would be connected first to a relay that is interlocked with some conditions/status other then key to START. They would be:

• automatic transmission should be in neutral/park with light indicated;
• alarm/security/immobilizer is inactive/OFF.

Good luck and Thank you for using FixYa. Happy Holidays.

the only way to reset an alarm is to disconnect the battery cables.

there is no such thing as an alarm reset switch.

My suggestion would be to go to autozone, they sell replacement key pads.

I took it to the Ford dealership. Don't ever let a shade tree mechanic work on your electrical. It turns out, someone wired the alarm totally wrong. Which shorted out my headlight switch.