Porsche Enthusiasts Club Forum

I am trying to piece together the original alarm function and the rubbish that has been added to my car over the last 30 years.

The original alarm, used to activate when the doors were locked with the normal (not special) key. This would arm the doors, hatch and hood. The door knobs would flash (LEDs). If activated, the horn would sound and engine would be immobilised.

None of that is functional, the alarm relay is missing from the fuse box and the module box is missing from the foot well. This is a simple alarm and I want to get it going. If my description is wrong, please do let me know.

BUT I have also found, an engine immobilizer by Auto Watch, this stops the car starting until I touch a little piece of black plastic on the dash, which then allows me to start the car. I am guessing it has been plugged into the same pins in the old alarm that immobilised the engine when it was activated. Happy to removed this system if I add the old alarm back.

Finally, there is this box by the battery, which I think is a Hamilton and Palmer system (picture)
which also does seem to connect to passenger foot well where the old alarm was once located. I do not think this alarm works, there are two movement sensors by the rear windows (that look like the round sensors on the dashboard for the heater). These , I think are sonic sensors for this system. Neatly installed but not working. This system I think was added by UK Porsche dealers. I want to remove it. And as I said and go back to the stock alarm.

Do the descriptions / assumptions sound right to every one that know the 944 histories? Mine is a 1989 2.7 944.

Any issues people think I need to watch out for?

Thank you

That sounds about right

The box by the battery used to connect to the ultrasound sensors so that’s in the bin
You can find alarm units on the bay of fleas quite often and as they are dumb units there should be no programming required

Your big problem will be working out where all the plain black wires go

Thank you. Weekend project me thinks. On sight, I am guessing that the old Sonic alarm and the current immobilizer tap in to the old factory alarm plugs, that immobilise the DME Relay, so may have to bridge the jumpers in the original plugs......I'll work it out some how. Wire by wire

I have been dwelling about answering this post with some tips and tricks for removing these units, which I can often do completely with restoring the looms in about an hour to two hours, but I am concerned that it will be seen as a step by step instruction manual of "how to steel an 80's and 90's model Porsche if you have time on your hands"

If you are in this process and would like some help, and you are a TIPEC member, my contact details are usually in the club magazine under technical advice.

There are some tips, which make this much quicker and easier to do.

These models have two levels of security.

The first level is the factory system, which in your model year, usually just consists of a alarm control box, about the size of a pack of cigarettes in the passenger foot well, with a couple of wiring connectors, one large and one small, right next to one another. Sometimes, if optioned, you might also have a key lock behind the drivers door as well, and also some other factory fit options (such as some later models having ultrasonics built into the rear quarter panel trims.

The second level is dealer installed and manufactured by Hamilton & Palmer near Cambridge in the UK. These were retrospectively granted Thatchum insurance approval as a Thatchum Cat 2 immobiliser, but unfortunately are not installed to Thatchum Cat 2 standards, which gets some people into trouble if thier car is stolen and recovered and an engineer checks it out.
These units normally plug in where the relay goes and provides a new connector for the relay, to keep the original system in the loop.
They also usually have one, two or three other black boxes and you can usually tell those systems and their wiring, by having black glossy insulation taped up looms, rather than the factory fabric taped looms, with wiring going off to the fuse box and ignition barrel, as well as to a receptacle for the immobiliser key fob, and off to an LED (the original factory system has no stand alone LED that flashes, only in later models does it have the door pins with built in LED's which flash, so if you have an LED in the centre console for example, it is either one of these systems, or an aftermarket system).

It is not unusual to find a 944 or 80/90's 911, with the factory alarm, the dealer fit alarm, and quite often 1, 2 or 3 other aftermarket alarms which have never been removed.

It sounds like you are doing the right thing, as usually with my cars I tend to remove all the aftermarket systems, and the dealer fit system, and fit something more modern, robust and thatchum approved such as a Toad Ai606.

The wiring standards of the dealer fit install are often very poor, but also the dealer fit security system circuit boards are not of great quality in modern standards, so these two points can make the systems very unreliable.

But if any valid member wants more in depth information of how to remove the system, I am more than happy to supply this, it is not rocket science, but there are some pitfalls to avoid and some really easy ways to approach the process.

With specific advice to your question, yes the box you found is a gutted standard ultrasonic motion detector as used by many alarm manufacturers in that era, but with the two sensors usually remotely mounted, rather than sitting in the two gromets you can see in the box (originally designed to go onto the dashboard).. In with the wiring where the original cigarette box sized relay would plug with two connectors (often has HELLA) written on it, usually has been removed, with the dealer fit system plugged into its place, and the HELLA relay replugged into the dealer fit loom close by... So do not throw the HELLA relay away with the aftermarket stuff, just unplug the dealer fit loom, and plug the HELLA relay in where the loom unplugs (near the DME usually)

Then you just need to deal with the immobiliser and other wires, which I do not want to be too graphic about here.

Hamilton Palmer are still around,

they are located in kent and still supply the "USB" socket and can reprogram and supply keys for the late 944/968

Tel: +44 (0)1732 760022
Fax: +44 (0)1732 760033
Email: sales@hamilton-palmer.co.uk

sound advice from Jon as normal

Jon and Waylander.

Thank you for help. I really like the advice, reall helpful and also interesting history.

I want to strip it all out (safety) and start again. Will let you know how it goes.

Found 2 out of the 3 boxes in my 1990 944 Turbo when I was putting it back together after the respray.

I didn't want to cause any issues so left them where they reside... for now at least...

And yes I have an aftermarket Laserline system now which (touching wood) works fine and has done for the 12 years I've had the car.

Update on Alarms!

We removed immobiliser from behind steering wheel that had tenticals everywhere. Fully removed, every wire.

We removed the Thatham UK Porsche dealer alarm (box by the battery), this strangely went to the rear quartlight ultra sonic sensors that I had originally understood the Porsche manufacturer alarm used But we checked it several times and they were connected to the Thatham. This had tenticals everywhere also. Fully removed, every wire.

Finally, we found the control box for the original West German Porche alarm and plugged it back in. The LEDs on the door knobs lit up (when we locked) the door.

Now we are back to the original West German manufacturer alarm only, what does it do?

What we know is
- Horn behind fuse box under bonnet
- I have an Alarm Rely to add to fuse box (I haven't)
- Control unit back in foot well.
- It seems it arms when doors are locked with standard key. (No separate lock). We only know it arms because the LEDs light up on the door knobs when we arm it. (With out the relay, guessing not alot would happen).

What was it meant to do and whatsets it off?

Any advice helpful!!!

the factory alarm instructions are all in the owners handbook

it sounds when the doors, hatch or bonnet are opened with out using the key, or if the radio is disconnected, if the car has been attempted to be entered the light pattern changes on the door buttons,

it does not imobilise anything as far as i know

Thank you. It seems to be fully functional!!! Who knew, it would have a pulse after all this time!

I would like rid of the USB type Hamilton Palmer as its a pain, the key only works one way round, but its part of the original car so although I dislike it a lot, I will keep it

I still have this. Most times it works fine, sometimes the key needs a wiggle. Often wondered how easy it is to install a new socket?

They are easy, you can order a socket from them £60 and just cut and shut one wire at a time

I bought a brand new one with no keys all in a box for £20, I have a new socket but I wanted a new box as mine is silent, it used to bleep really softly, now nothing

I cant change it as all the wires are black and no plug in the box under the seat

I will change my socket when I fit the cruise control while I’m on quarantine, high risk and all that crap

But my thoughts go out to Italy, they are really suffering

Perfect. Thank you.

Back on a fully working 1989 original alarm. Works great.

Just for interest I found the original alarm box in my car when I was putting it all back together last year, most of the wires have been cut but I was still not sure what would happen if I removed it completely so it still lies in its original location. My car had a laserline cat.1 alarm / immobiliser fitted at some point in its life and it still works great today - especially now I found that the false alarm during hot weather was down to the bonnet switch activating... turns out the metal "striker plate" that pushes down on the switch under the bonnet had bent slightly over 30 years and was releasing the button enough when the bonnet was hot to set off the alarm! little push back down and now no more false alarms