alanshaw

Car alarm system Help Please.
My remote was working perfectly when locking and unlocking the doors etc. but although the indicators flash to let me know the car alarm is enabled and disabled and doors lock and unlock with the remote the alarm never chirped or sounding when setting off the alarm. I decided to check this out and found the siren was completely burnt out I purchased a replacement one not factory. But when I cut the original cables to check the + - and switch cables I think I must of shorted them out or something. So now the remote will not lock or unlock the doors from outside the vehicle and indicators no longer flash to indicate this. But when I put the key in the ignition and turn to on the indicators flash three times and I can operate the remote to lock and unlock the doors whilst inside the car plus i can still start the car normally Any suggestions on how to get this back to at least locking and unlocking from outside using the remote and not the door keys?

WhiteBird00

iTrader: (4)

There is no siren for the factory alarm (it uses the horns) so I wonder what kind of alarm is installed. There was an add-on to the factory alarm that was available through GM dealers (the Hornet 700T from DEI but repackaged for GM). It added additional features such as a siren and optional sensors such as motion detection or glass breakage. However, it wasn't very popular so it is not very likely that you have one. It is much more likely that you have an aftermarket alarm such as a Viper installed.

Have you checked fuses? It sounds like the BCM isn't getting power while the ignition is off but it is when the ignition is on. There are several power inputs to the BCM from different fuses. The two that provide constant (battery) power are the PWR ACCY and the COURTESY fuses. Check those first and see if it resolves the problem.

alanshaw

Thanks for replying. It definitely is a factory fitted from new and everything works except the siren because it's internal batteries leaked and blew up the sirens circuit board. I checked out the alarm module which is in the driver's side footwell all original and relplaced the fuse to the siren. I just wanted an easy fix by simply replacing the siren which has 3 wires and it seams to be operated by a resistance and not a usual 12v. ??? All the rest of the system works correctly. I still get the hazards flashing led showing armed and disarmed etc. I am even still using my original key fob as the car has only 30k and has been kept in excellent condition.

WhiteBird00

iTrader: (4)

Sorry, that is simply not possible. No 4th generation f-body ever came with a factory alarm that included a siren - they all used the horns. The "alarm module" in a factory system was the body control module (BCM) mounted behind the glove box which also managed the courtesy lights, keyless entry system, and several other body functions. Even the factory authorized, dealer installed accessory alarm system was just an add-on for the factory keyless entry system. It was a repackaged Hornet 700T made by DEI and did not include a siren either, although one could be purchased separately from DEI. It also came with its own LED indicator but it was possible to modify the system to use a factory LED mounted on top of the dash next to the defroster vent.

alanshaw

Thanks for the info. I will have to pull the alarm module out from my foot well perhaps it will have some clues as to the maker. It must have been well installed as it appears to be all connected into the factory loom as I can't see any evidence of spiced wires etc.

Regards Alan