Alarm not sounding....

Hello,

On my '01 P38 lately every time the alarm goes off the horn does not sound. The system works since when it's tripped from the inside of the cabin you can hear the clicking of the relay on and off but the horn doesn't sound. Similarly if you leave the bonnet open and try to lock the car with the keyfob you don't hear the beep either as you normally would. There are no fault codes. Has the alarm horn quit working? Is there a relay I can check before testing the alarm horn?

Any help is greatly appreciated.

Thank you,

Calguy

calguy said:

Hello,

On my '01 P38 lately every time the alarm goes off the horn does not sound. The system works since when it's tripped from the inside of the cabin you can hear the clicking of the relay on and off but the horn doesn't sound. Similarly if you leave the bonnet open and try to lock the car with the keyfob you don't hear the beep either as you normally would. There are no fault codes. Has the alarm horn quit working? Is there a relay I can check before testing the alarm horn?

Any help is greatly appreciated.

Thank you,

Calguy

Click to expand...

The alarm has it's own sounder, it does not use the car horn.
The beeps inside the car are from a little speaker behind the instrument binnacle.
Carpet wet in the drivers footwell by any chance?

Thanks for the reply. You are right on the alarm having it's own horn as the normal horn works well. I only hear a clicking sound when inside the car, it's as if though the alarm horn quit working... No water in either footwells. Is there a relay for the alarm horn/transponder. I recently changed the battery and up until then it worked fine. I've synced the kefob and it works too just the alarm horn won't sound...

calguy said:

Thanks for the reply. You are right on the alarm having it's own horn as the normal horn works well. I only hear a clicking sound when inside the car, it's as if though the alarm horn quit working... No water in either footwells. Is there a relay for the alarm horn/transponder. I recently changed the battery and up until then it worked fine. I've synced the kefob and it works too just the alarm horn won't sound...

Click to expand...

If you have the B Bus sounder, it has an internal battery, if you didn't follow the correct proceedure when changing the battery the sounder should have let rip, this may have finally knackered the internal battery if it was already too weak to operate the sounder.
Operation is from the BECM. Look at RAVE for details.

Is the sounder connected in the engine bay?

Mine wasn't when I bought my car.

Thanks for the responses. I don't think the alarm was tripped when the battery was replaced as the battery was completely dead. +1 on checking if the bbus is connected. Unfortunately RAVE isn't too detailed on where the connector for the bbus is located. Is the connector under the right side bonnet latch? I saw an image online of what the bbus looks like and where it's located (under the fuse box in the engine bay). If it's not connected then I'll reconnect it but if it is would I need to get a replacement bbus and all would be well or is there a fuse that possibly went out.

Thank you,

Calguy

Mine isn't the BBus connector so I'm not sure where it is.... but the standard sounder connector is just next to the sounder on mine, or at least very near it, I can't quite remember TBH!

Thanks for the response. I'll have to take a look around that area, chances are it could just be unplugged otherwise I'll probably have to get another unit and drop it in and see if that does the trick. If the battery of internal to the siren can that just be replaced? Isn't it a rechargeable battery?

Best,

Calguy

I'd assume it is a rechargeable yes.

When I bought mine the battery was on the way out, and I assumed the previous owner was bored of the alarm going off all the time so he just unplugged it! Once I plugged it back in it's worked fine.

I thought the BBus ones were for the USA market only but I might be wrong.

The sounder is between the battery box and the fuse box low down, the connector is on the unit. Mine has the Bbus sounder and it's UK spec late 2000, it's never worked which suits me.