Alarm/Locking computer fuse URGENT!

[savvas_cy]

I figure out that when I lock my 1999 Boxster and as soon as the alarm goes on burns the fuse of the alarm/locking computer.Also when i press the lock button twice just before the brief sound of horn the fuse is dead again.

That make me belive that there is something wrong with horn but is working ok.the alarm siren is working ok too.

Does that mean that i need to change the alarm/locking computer.Is there a possibility to fix it or disable the alarm and just have a central locking?

Please help me.

Really urgent!!!!

Thanks.

[Stefan]

The first thing I would do is check for moisture under the seat. If it is moist, I highly recommend you dry it out before using the car any more. You don't want to do further damage to the electronics.

[savvas_cy]

It is not dry.I checked this first.2 months ago i change the fuse again and it was working ok.No probelms.Now as soon as the siren start the fuse is dead.

I know I have to take the car to Porsche but will they know how to fix it?

I am from Cyprus.I dont know if there are any persons that can fix Porsche.

[savvas_cy]

Sorry for the mistake in previous post.

I meant is dry!No water no misture no nothing.Is really dry.

[mikes_box]

sounds like an electrical problem that's causing a short when the siren turns on...check the wires and make sure nothing is lose or touching metal...

[juniinc]

1998 Porsche Boxster Security Information

Constant 12V+ Red/White Ignition Switch Harness

Starter Yellow Ignition Switch Harness

Ignition Black Ignition Switch Harness

Trunk Pin Brown/Red (-) Trunk Light

Parking Lights Gray/Black Gray/Red at Light Switch

Door Trigger Brown/Yellow (-) Driver's Kick Panel

Door Lock Brown/White (-) Driver's Kick Panel

Door Unlock Brown/Red (-)

Horn Wire Brown/White (-) Behind Relay Panel

I've seen a few cases similar to your situation. In fact, last week we had a car came in for the same symptom and we end up finding a faulty micro switch on the driver's side door(of course,,,). Yes it is the same switch serves as window lowering. In his case it was the micro switch (shorted register) that caused a short . then it kept blowing the M535(alarm module) fuse. My guess is probably your door trigger , center console contact or horn wire..

And it is impossible to just disable your alarm feature, It is possible on 987's you can always pull your horn fuse out see if that helps. lol

have your code read! (PST2). You might have to replace your alarm computer module.

I figure out that when I lock my 1999 Boxster and as soon as the alarm goes on burns the fuse of the alarm/locking computer.Also when i press the lock button twice just before the brief sound of horn the fuse is dead again.

That make me belive that there is something wrong with horn but is working ok.the alarm siren is working ok too.

Does that mean that i need to change the alarm/locking computer.Is there a possibility to fix it or disable the alarm and just have a central locking?

Please help me.

Really urgent!!!!

Thanks.

Edited October 18, 2007 by juniinc

[savvas_cy]

How can it be micro switch in door or in center console?central locking is workinf ok.All doors and hoods lock and unlock.The fuse blows just when the alarm try to enable the horn beep.I am not sure if my description make sense to you :)

I am not an expert.I appreciate your help.Can you please tell me detailed what i have to look for

Thanks.

[juniinc]

Ok, That's just the way your central locking system works . As soon as you push your remote button to lock the car, it also automatically arms your alarm when that happens your M535 computer is detecting a short in the system that is causing your blown fuse problem. I wasn,t saying it is the micro s/w u are facing ,that was just for an example since it was the 1 of many alarm contacts. It could be that brn/wht horn wire as I showed or u might need a new M536 then reprogrammed.

How can it be micro switch in door or in center console?central locking is workinf ok.All doors and hoods lock and unlock.The fuse blows just when the alarm try to enable the horn beep.I am not sure if my description make sense to you :)

I am not an expert.I appreciate your help.Can you please tell me detailed what i have to look for

Thanks.

Edited October 17, 2007 by juniinc

[Loren]

On an RoW car (which this is) it would be M536 and it is slightly different than a US/Canada M535 car.

[savvas_cy]

I found the problem.It was the horn wire.So i cut it :)

Now I dont have any horn sound when the alarm beep.

Am I going to have other problems now?

I hope not...

Thanks for your help guys!!!!

[juniinc]

I knew it! I'm just glad that you didn't have to purchase the new computer unit. I remember what your local mechanic guy told you, something like new unit is needed then reprogrammed-WOW,,, Can u imagine spending around $1000 and not having your car for a few days.

I found the problem.It was the horn wire.So i cut it :)

Now I dont have any horn sound when the alarm beep.

Am I going to have other problems now?

I hope not...

Thanks for your help guys!!!!