SL500 129 alarm immobiliser

[chrisssl500]

I am having trouble with the alarm immobiliser (warning lights coming on, engine cutting out etc) it looks like an after market one has been fitted but it is controlled by the Merc key fob?? I have swiched it off but then the central locking and the red and green lights on the door don't work. I want to put it back to the standard Merc system. Any advice would be greatly appreciated.

 

[pascal]

What year is your car, and what country was it first registered in?

 

[chrisssl500]

Hi Pascal
Its a '96. I assume its a uk car

 

[pascal]

I would have thought that the MB alarm was not fitted to UK cars around that time, as it did not meet the 'thacham' grade. Scorpion made (specifically for MB) the alarms that were fitted to UK cars. Its the one with the little black and red emeg keys. The scorpion alarm fitted to my SL is MBSS 2b (uk car). LED on sensors and on drivers footwell where key disarm key goes.(no LEDs in the door though)

 

[chrisssl500]

Mine sounds completely different to yours. The red and green lights are actually in the drivers door handle on the outside of the car. Is this not standard on this model? There is nothing in the footwell. To add to the problem there is a Toad immobiliser fitted. I think its over to the auto elecricians to sort it out. I am very interesred in the red and green lights in the door handle though! Anybody else got this system?

 

[justinb]

HI,

Yep, my 500 sl r129 has got red and green lights in both door handles and the boot. I had problems with the alarm on mine too. So I disconected it for a week. (its in the boot behind the battery cover) and this seemed to sort it out. Well at least its working for now!!

 

[grober]

the red and green lights "thingy" sound like the standard merc remote locking system. I have a feeling the alarm is triggered from this door locking mechanism. The alarm arm/disarm signal line may be spliced into the door locking circuits. Try having a look at the wiring beside the vacuum pump. Its normally below the rear seat in saloon cars but in an sl dont know??? Just make sure the alarm is in a disarmed state before disconnecting !!!

 

[GregE240]

I don't know if any of you have the same alarm as me, but I have 2 ultra sonic sensors in the car, one on each side of the dasg screwed to the A pillar. One of the holders has broken on mine, any idea where I could get a spare from?

Thanks,
Greg

 

[jberks]

Both of you have the same problem in that the first thing you have to do is to identify what alarm it it. Both are non MB after market units fitted either by the owner or dealer at some point, so whilst similar, they may not be the same. I have an alarm spliced into the central locking on My C, and what you describe on with the lights etc sounds identical to what I had.
I'd start by finding a component such as a control box,and getting a manufacturer's name off it, though to be fair, its often cheaper and less hassle to replace the whole alarm, than to try to find parts for them.

 

[GregE240]

Thanks J, thats what I suspected.

That said, I have the ENTIRE history of the car (I bought it as a 1 owner, with the previous owner being a family friend who was fastidious with their receipts).

I'll have a check through the paperwork tonight and see if I can identify it. Also, I found the alarm siren under the bonnet yesterday so I'll see if theres a manufacturers label on it.

Cheers,
Greg

 

[pascal]

Those little holders ate delicate enough greg. You could use a bit of bluetak or even glue to hold it down. Is it a Scorpion alarm?

 

[GregE240]

Those little holders ate delicate enough greg. You could use a bit of bluetak or even glue to hold it down. Is it a Scorpion alarm?

I don't know - will check tonight.