83 SC - How to deactivate alarm?
 

How to disengage/disconnect the alarm?

Was charging up the battery on my 83 SC, after not driving it for over 3 months. When I plugged the charger into the wall, the alarm turned on.

This was a complete surprise to me. I've owned the car since 2009 or 2010 and never knew there was an alarm?

It it matter of finding the correct wire and unplugging/cutting? Or will that disengage the ignition as well?

Tried to look for the alarm horn/speaker, but not able to find. Anyone know where to look?

Thanks!

Suggest you try to figure out if it's factory or aftermarket. Most work by disabling the fuel pump circuit. The factory siren is located in the front belly pan.

The alarm schematic is in the back of the Bentley. I was recently inquiring about this and didn't have much luck getting my questions answered. I *think* the alarm brain can be found behind the blower motor cover in the trunk.

Maybe that info will get you started in the right direction...

Look for a place to insert a key, in the rear of the driver's door, just above the latch. If present, it will be a factory alarm that takes a special key to disarm. The key is slender, marked Hul and nothing to do with your ignition key. If you have an aftermarket alarm, can't help you.

JR

On an 83 there's large odds that it's an aftermarket alarm.

If that's the case the best bet is to trace all the wires, get rid of it all and put the wiring back to stock.

I've done it several times over the years on 911s. It's not that bad, the aftermarket wiring is usually very obvious.

+1

I was surprised at the mountain of wires I removed.

My aftermarket control box was behind the carpet on the left side near your left leg. There was a lump there and pretty evident. Siren was way back (well, forward) in the engine compartment.

Cheers mateys! Thanks for the info to get me started.

Will look at the door jamb to see if there's any key insert clues. Never noticed, but never looked for it either.

There is a "horn" looking thing that is installed in the "frunk" at the very front ---towards the bumper. Looks to be very clean install, like it was done by factory --- with sealer gasket and all. Not sure what that is, will try to post a pick

I've traced some very thin light gauge wire that looks like it does not belong --- well you know with the German engineering, everything is over-engineered, so with a think wire, might be aftermarket.

So, front belly pan means the underside of the car? Accessed from under car? Or within the 'frunk'? I sense that the sound/alarm is coming from the underside --- belly.

Blower motor -- in the 'frunk'? May be in what is called the "smuggler's box"?

Thanks for chiming in.!

The "horn looking thing" in the front trunk might be the blower for the front A/C condenser. A factory alarm horn is probably going to be underneath the car.

JR

The factory key switch is on the end of the drivers door, if you don't have the factory alarm there's a plastic plug like this (on the left)
http://forums.pelicanparts.com/uploa...1440357089.jpg

From what I remember, the factory alarm horn sits in the "smugglers box" just above the A/C stuff.

Here's some info on bypassing the stock system

http://forums.pelicanparts.com/porsche-911-technical-forum/766645-911-sc-alarm-bypass.html

There was a recent thread where the alarm horn was under the steering rack shield next to the fuel pump.

http://forums.pelicanparts.com/uploa...1440361216.jpg
http://forums.pelicanparts.com/uploa...1440361244.jpg

Same for me

http://forums.pelicanparts.com/uploa...1440361502.jpg

Thanks Bob --- unfortunately was not there in my car

Ditto on factory alarm horn being located next to steering rack under the metal protector plate

javadog --- yes something like that seen in the location you described --- see post #11.
Thanks for chiming in!

That pic is of your regular horn, not alarm horn.

The factory alarm horn is a small disc style horn, maybe 3.5-4 inches wide or so. It's around the front crossmember.

There's no key in your door.

Very few SCs came with a factory alarm. Yours is aftermarket.

You need to just start digging around, under the front passenger floorboard, up under the dash, in the front trunk area, to find where they located the brain, horn, etc. and then just start tracing wires.

Once I find it,is it just a matter of removing complete sys? Or need to rewire/reconfig other electricals? #NIGHTMARE

Thanks 'Mac'!
Will dig deeper!

It's may not be quite as simple as removing things, but it's pretty close.

If you have some kind of starter or fuel disable, you'll have to deal with that. The alarm will be placed in line in the system, so when you remove the alarm you'll have to put the wiring back to stock.

So it really depends on what you have.

If you have no experience with electrical or alarms, or don't understand the general theory behind it, it could get a little tricky.

But if you work carefully, take pictures of everything you disconnect, disconnect one wire at a time, you should be ok. Worst case scenario, if you photodocument every wire you disconnect, you can reconnect everything and be back where you start.

First step would be to try to locate the brain and the horn, and any other parts (like motion sensors, etc.)

Hopefully it's a simple system. Modern aftermarket stuff is fairly simple plug and play, but a lot of the systems from the mid 80s were unfortunately fairly obtrusive on the factory wiring.