355 alarm siren repair

I went to replace the battery on mine and it has no screws to open it up. I guess the PO had replaced the alarm at some point in time with a new one. Anyone ever open one up that doesnt come apart ?

 

Yes, they can be cut open along the seam. Batteries plus can solder new batteries in.


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Dremel tool?

https://www.ferrarichat.com/forum/posts/140002974/

Looks like this guy used something similar on his Ferrari 360 siren (see 3:10 mark)



Has anyone tried to find the (sometimes) compatible Corvette siren recently? GM P/N 5213135. They seem to be NLA.

 

Yes, Dremel works perfectly.


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I did not think it awas sometimes compatible but was compatible just need to cut the switch.
Is my memory going again?.

 

Ah... I meant "easily" compatible.
The old sirens have a connector on the end of a permanent 9" (?) lead. The newer Corvette type has a connector embedded in the back of the siren case and normally requires a very expensive adaptor to make it compatible with the car (as is used on 360's, 550's, etc). Or, you could cut off the lead (& plug) of the old siren and solder the wires onto the pins of the new Corvette type (which I imagine would look a little less OEM). ... Not that the concourse guys are going to go looking for the siren.

 

Gotcha

 

The Bosch siren unit was identical. Same plug receiver. No extra wires.


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Thanks Bob maybe i am not losing my mind??

 

Thanks Taz


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For clarification:

Siren with integral pigtail (lead) and screws in the case:

https://www.ferrarichat.com/forum/posts/145835802/

Siren with no integral pigtail and plastic case welded (upper photo)

https://www.ferrarichat.com/forum/posts/141382420/

 

Has anyone bench tested their siren?

I had the red LED on permanently and, as I have done once previously, replaced the rechargeable battery. However, on reconnecting the siren, it no longer works. There was some corrosion on the connector pins on both the siren and the car, so I repinned them and found the copper core of the black wire on the car loom to be a dull black/brown colour, so there is some corrosion present, although it was chirruping happily before I replaced the battery so, while not ideal, shouldn't be an issue. I'm wondering now if I disturbed something on the board while replacing the battery - does anyone have any instructions for bench testing it please?

 

If you don't know this video it might help:

 

Thanks but I've done all that (it's my second rodeo) and my problem is that the siren no longer works.

Was working, took off car, replaced battery, no longer working.

 

I doubt you can bench test it. The Immobiliser ECU probably has to send a particular signal to arm/disarm the siren. I don't believe it's a simple voltage. I'm sure you've seen how complicated the circuitry is.

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Is the immobiliser arming/disarming properly? Is the light flashing after you've disarmed the alarm?

How is your soldering? The legs on the batteries probably have to get a little warm so that the solder can stick to them.

Did you make sure the speaker was plugged in?

Were there 2 standard, green, Varta batteries in there or an aftermarket battery?

 

Everything is working properly except the chirps (and my dash LED is still permanent red). My siren has a single replaceable battery pack under a plastic retainer. I think I'll take the board to my local electronics repair placed to be assessed. I've already repaired it once before by touching in broken traces.