Alarm won't switch off !

Alarm won't switch off !

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johntom

Original Poster:

247 posts

202 months

Sunday 29th November 2009
quotequote all
Hi
I went to get in the car (400se) this morning, only to find the remote alarm/central locking isn't working. The red led lights on the remote (12v battery showing 11.5v, also have a spare) but the car doesn't unlock or switch off the alarm? The history says the alarm is a 'Serpi Star', model 'Detroit'?
When i unlock the car with the key the alarm still won't go off (led on steering column). I have tried disconnecting the battery which does cause the central locking to operate (unlock,so it's not the motors), but this obviously doesn't disable the alarm. With the led on the steering column on I can start the car but only for about 1 second then it cuts out, there is a separate immobilisor which seems to work ok. There are 3 inline fuse on the inner wing next to the siren, one is definitely for the siren, removing all 3 doesnt disable the system.
Does anyone have this model alarm fitted?
Does it disable the coil etc?
Any advice welcome, alarm receiver failed?

Wedg1e

26,760 posts

264 months

Sunday 29th November 2009
quotequote all
Pull the cover off the remote and see if it has a small screwdriver-adjustable trimmer in it (usually about 6mm square with a cross for your screwy), it could be that the transmit frequency has drifted off a bit. Tweak the trimmer no more than about 30 degrees in either direction and retry it.
Serpi Star (according to my book of words) were also sold badged as 'Waso', there was a lot of that going on in the early 90s.... Sterling, Foxguard and at least one other brand were all the same electronics in a different importer's box.

johntom

Original Poster:

247 posts

202 months

Sunday 29th November 2009
quotequote all
Hi
no joy with the transmiter as suggested, neither one worked. So I have taken the alarm system out completley as there is a separate immobilisor which does function. The control module was date stamped 1990 so I guess its given good service. I have order,via ebay, a remote central locking kit which i will use to replace the alarm operated central locking. Thankfully, the car now runs again.

adam quantrill

11,535 posts

241 months

Tuesday 16th January 2018
quotequote all
Wedg1e said:
Pull the cover off the remote and see if it has a small screwdriver-adjustable trimmer in it (usually about 6mm square with a cross for your screwy), it could be that the transmit frequency has drifted off a bit. Tweak the trimmer no more than about 30 degrees in either direction and retry it.
Serpi Star (according to my book of words) were also sold badged as 'Waso', there was a lot of that going on in the early 90s.... Sterling, Foxguard and at least one other brand were all the same electronics in a different importer's box.
interesting I think I have seen one of these, looks like the spectrum analyser at work will be tried out tomorrow! Any idea of the ideal centre frequency? The working fob has a limited range so it may be a little off.