993 Aircon & Alarm

[Wozy68]

Afternoon all.

My early 993 (Dec 93, and was so early it came from new with a 964 service book, go figure) still has the original built in alarm system. There is an immobiliser and the car sounds the horn for 30 seconds if the alarm is set off. i.e. it does not have a separate siren or the key fob thingy to open the doors, set the alarm etc.

The problem I'm getting is that after locking all the doors, a minute all so later the alarm (horn) starts kicking off. This means that I have to leave the car unlocked which is a pain.

The other day I noticed that after a drive, I'd switched the engine off, got out the car and realised I'd forgot my sunnies. Came back and noticed that the aircon unit was quietly buzzing away to itself. ...... Is this normal?

Anyway left the car awhile came back and the aircon unit had stopped buzzing, locked the car up in the hope it wouldn’t kick the alarm off, and hey presto, not a murmur.

So the reason for my post is, would the aircon unit whilst buzzing away (and do they all do this) be a drain on the battery, and therefore would the alarm think it was someone trying to break in and set the alarm off?

Thank you in advance if anyone knows.

[davek_964]

No.

The fan for the air con unit (blows over the interior temp sensor I think) runs for about 15mins after you turn the car off. Entirely normal.

The alarm is Hamilton and Palmer by the way, in case you didn't know.

[Wozy68]

davek_964 said:

No.

The fan for the air con unit (blows over the interior temp sensor I think) runs for about 15mins after you turn the car off. Entirely normal.

The alarm is Hamilton and Palmer by the way, in case you didn't know.

Thanks for that, but its not a fan sounding noise, more a buzzing from the aircon head unit.

Is that what you mean though ....

[davek_964]

Wozy68 said:

Thanks for that, but its not a fan sounding noise, more a buzzing from the aircon head unit.

Is that what you mean though ....

Yes, that's when I mean. It's a tiny fan - you can actually reach up the back of the air con unit and feel it.

[cd1957]

Hi you have the standard factory alarm which can have the "events" read with a diagnostic tester,this will tell you whats been setting the alarm of,its not an H & P system.

Chris

[Wozy68]

cd1957 said:

Hi you have the standard factory alarm which can have the "events" read with a diagnostic tester,this will tell you whats been setting the alarm of,its not an H & P system.

Chris

Cheers Chris,

You are a long way from me, would my local OPC still have the kit required do you think?

[cd1957]

Hi Wozy,yes all OPC can still connect to the car.

Chris

[Wozy68]

Just to finish this off.

Thank you 'POPE' for suggesting to check for a green wire behind the car stereo.

If your 993 alarm sounds it may well be a green coloured wire that earths to the ICE chassis. Mine had only came lose, and I'm guessing this was caused by pushing the new CD player into location. I pushed the cable firmly back on and now no problems.

Just something to remember if replacing the stereo at any time, and if replacing the holder to reattach the green cable. Saved me investing in a new alarm system as it was sure getting me down.