993 roof power
Discussion
Wozy68 said:
Have a look at the stereo chassis holder. Is there a (I think) brown wire connected to it?
This was {on the early 993 cars at least) the anti theft for the H&P system and set off the alarm if someone tried to nick the stereo. It had come detached when I’d pulled the original stereo and so didn’t see it when I installed the new one.
I’d never had sorted it but the great all knowing ‘Pope’ told me about it when I’d asked on here back in the day and low and behold it was detached and lay inside the dashboard
On mine it was well known for setting the alarm off for no good reason and especially in the middle of the night. Reconnected it and never had an issue again.
Yes, this is it (pic below). It was still attached with the after market stereo but I detached it when I changed the stereo chassis. and it’s too fiddly to reattach but I have to somehow. This was {on the early 993 cars at least) the anti theft for the H&P system and set off the alarm if someone tried to nick the stereo. It had come detached when I’d pulled the original stereo and so didn’t see it when I installed the new one.
I’d never had sorted it but the great all knowing ‘Pope’ told me about it when I’d asked on here back in the day and low and behold it was detached and lay inside the dashboard
On mine it was well known for setting the alarm off for no good reason and especially in the middle of the night. Reconnected it and never had an issue again.
Was it supposed to set off the alarm if someone ripped out the stereo? Not quite sure I understand as it was attached to the stereo chassis, not the back of the stereo? One presumes that a self-respecting 90s stereo thief would have bothered to bring along the simple double-prong stereo removing tools which would have removed the stereo and left the chassis in place? Or was it designed to detect the stereo being removed only? It was attached in a particular way…
Currently, the alarm is not going off all the time, even though it is detached. It was just randomly going off every couple of days but I unplu the stereo now just in case.
Spent a very pleasant afternoon with A993LAD, partly purging H&P obsolete gumph from the boot and the dash (but mainly working on the roof issue). We got the auto roof/window closer, the alarm upgrade and CD changer (which probably wasn’t H&P).
Orangecurry said:
...yes yes fixing your problems, all well and good....
But where are the photographs of the 993x2 next to one another????
Yes that was a bit silly! With a gorgeous 356 in the middle!But where are the photographs of the 993x2 next to one another????
Our LAD is the world expert on 993 convertible roofs. I learned more in 2 hours about them than I’ve learned in 10 years of ownership! He’s a dab hand at the electrics too.
I’m going to pop back down when I get the roof control box back off Tore, you should join us!
chrisgaia said:
Wozy68 said:
Have a look at the stereo chassis holder. Is there a (I think) brown wire connected to it?
This was {on the early 993 cars at least) the anti theft for the H&P system and set off the alarm if someone tried to nick the stereo. It had come detached when I’d pulled the original stereo and so didn’t see it when I installed the new one.
I’d never had sorted it but the great all knowing ‘Pope’ told me about it when I’d asked on here back in the day and low and behold it was detached and lay inside the dashboard
On mine it was well known for setting the alarm off for no good reason and especially in the middle of the night. Reconnected it and never had an issue again.
Yes, this is it (pic below). It was still attached with the after market stereo but I detached it when I changed the stereo chassis. and it’s too fiddly to reattach but I have to somehow. This was {on the early 993 cars at least) the anti theft for the H&P system and set off the alarm if someone tried to nick the stereo. It had come detached when I’d pulled the original stereo and so didn’t see it when I installed the new one.
I’d never had sorted it but the great all knowing ‘Pope’ told me about it when I’d asked on here back in the day and low and behold it was detached and lay inside the dashboard
On mine it was well known for setting the alarm off for no good reason and especially in the middle of the night. Reconnected it and never had an issue again.
Was it supposed to set off the alarm if someone ripped out the stereo? Not quite sure I understand as it was attached to the stereo chassis, not the back of the stereo? One presumes that a self-respecting 90s stereo thief would have bothered to bring along the simple double-prong stereo removing tools which would have removed the stereo and left the chassis in place? Or was it designed to detect the stereo being removed only? It was attached in a particular way…
Currently, the alarm is not going off all the time, even though it is detached. It was just randomly going off every couple of days but I unplu the stereo now just in case.
Spent a very pleasant afternoon with A993LAD, partly purging H&P obsolete gumph from the boot and the dash (but mainly working on the roof issue). We got the auto roof/window closer, the alarm upgrade and CD changer (which probably wasn’t H&P).
I thought it was brown but maybe it wasn't. It was however definitely something to do with the early H&P alarm system and it did I'm sure have a spade connector on the end.
Maybe it was just another ground/earth for the alarm system.. rather than there for a security reason

What I do remember though was that it was a total PITA setting the car horns off (Mine is such an early 993 that it hadn't a siren) and it would set them off randomly sometimes days apart but more often daily in the middle of the bloody night. Plugged it back in and it never happened again. It just pushed on to a nib on the radio chassis via a spade connector if memory serves
By the time I replaced the radio and chassis at a later date, the H&P system had by then been removed.
Edit ,,,, Looking again at your pic. Yes that may well be it. Give it a try .
Edited by Wozy68 on Wednesday 23 April 17:45
Wozy68 said:
chrisgaia said:
Wozy68 said:
Have a look at the stereo chassis holder. Is there a (I think) brown wire connected to it?
This was {on the early 993 cars at least) the anti theft for the H&P system and set off the alarm if someone tried to nick the stereo. It had come detached when I’d pulled the original stereo and so didn’t see it when I installed the new one.
I’d never had sorted it but the great all knowing ‘Pope’ told me about it when I’d asked on here back in the day and low and behold it was detached and lay inside the dashboard
On mine it was well known for setting the alarm off for no good reason and especially in the middle of the night. Reconnected it and never had an issue again.
Yes, this is it (pic below). It was still attached with the after market stereo but I detached it when I changed the stereo chassis. and it’s too fiddly to reattach but I have to somehow. This was {on the early 993 cars at least) the anti theft for the H&P system and set off the alarm if someone tried to nick the stereo. It had come detached when I’d pulled the original stereo and so didn’t see it when I installed the new one.
I’d never had sorted it but the great all knowing ‘Pope’ told me about it when I’d asked on here back in the day and low and behold it was detached and lay inside the dashboard
On mine it was well known for setting the alarm off for no good reason and especially in the middle of the night. Reconnected it and never had an issue again.
Was it supposed to set off the alarm if someone ripped out the stereo? Not quite sure I understand as it was attached to the stereo chassis, not the back of the stereo? One presumes that a self-respecting 90s stereo thief would have bothered to bring along the simple double-prong stereo removing tools which would have removed the stereo and left the chassis in place? Or was it designed to detect the stereo being removed only? It was attached in a particular way…
Currently, the alarm is not going off all the time, even though it is detached. It was just randomly going off every couple of days but I unplu the stereo now just in case.
Spent a very pleasant afternoon with A993LAD, partly purging H&P obsolete gumph from the boot and the dash (but mainly working on the roof issue). We got the auto roof/window closer, the alarm upgrade and CD changer (which probably wasn’t H&P).
I thought it was brown but maybe it wasn't. It was however definitely something to do with the early H&P alarm system and it did I'm sure have a spade connector on the end.
Maybe it was just another ground/earth for the alarm system.. rather than there for a security reason

What I do remember though was that it was a total PITA setting the car horns off (Mine is such an early 993 that it hadn't a siren) and it would set them off randomly sometimes days apart but more often daily in the middle of the bloody night. Plugged it back in and it never happened again. It just pushed on to a nib on the radio chassis via a spade connector if memory serves
By the time I replaced the radio and chassis at a later date, the H&P system had by then been removed.
Edit ,,,, Looking again at your pic. Yes that may well be it. Give it a try .
Edited by Wozy68 on Wednesday 23 April 17:45
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