How can I disable the factory alarm system on my 85 Carrera?

ThePointman · ThePointman's Garage

Can you disable the factory alarm system without the key that fits in the lock inside the drivers door jam?

I have an aftermarket UNGO that I use that taps into some of the factory sensors that works great. However the car went in for a paint job and since then I can not start the car and the horn sounds repeatedly. I have determined that the horn sounding is tied into the factory alarm system. How can I shut it off without the door jam alarm key?

mschuep · 03-03-2006, 09:29 AM

I don't know. No offense, but I hope who does know PM's you the answer so people don't know how to bypass my factory alarm on my 85 Carrera.

ThePointman · ThePointman's Garage

Understandably this is done with the car unlocked and accessible. I have the ignition key just not the alarm key that should fit in the door jam alarm lock as mentioned. So I want to shut it off not really "Disable it".

syncroid · 03-03-2006, 11:13 AM

Pointman, There is a bypass that you can do where the factory alarm control unit lives. See picture attached.

mschuep, There is no need to worry about someone doing a quick alarm bypass on your car. To do this bypass is a major pain in the A$$! The alarm control unit is located in the front truck buried behind your heater/ vent system. All of that has to be removed to access it.

mike f · 03-03-2006, 09:13 PM

What about just pulling the fuse?

ThePointman · ThePointman's Garage

Thanks to everyone who replied. I opened up the door panel on the alarm lock side and discovered that the body shop had nocked one of the factory alarm wires of the back of the lock mechanism. I replaced it and problem is now solved.

Andrew Brunson · 03-04-2006, 01:35 PM

I had a problem with my 84 carrera. I also didn't have a key. You still may want to address this issue as the factory alarm has a rep for going bad and leaving you stranded. Mine went bad in my garage so it wasn't to bad. Pulling the fuse won't work.

Early_S_Man · 03-04-2006, 02:34 PM

Andrew, et al,

There is a CMOS chip inside the factory alarm unit ... a CD4011BE, IIRC ... that blows when the voltage regulator fails and causes Voltage spiking above 18 Volts!

Plecostomus · 03-04-2006, 03:30 PM

Cut the yellow wire.

Andrew Brunson · 03-04-2006, 04:02 PM

I removed all the wiring and alarm completely from my car. There is a wire at the alternator light if I remember right that jumps to the alarm. Also I had to change a hot wire at the fuse block. My car now is as if it left the factory without an alarm, no trace of wiring at all. This is to be a autox and track car with fun street drives.