G wagen immobiliser

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Sat, 01/10/2016 - 14:09
Lilas1998
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Hi I have a gwagen and while on holiday I mislead my key and fob, of course when I came back home the car was flat and would not start even after the garage changed the starter motor. I was wondering if you could advise on how to solve this problem. Many thanks.
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Sun, 02/10/2016 - 14:00
#1
Morpheus
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Re: G wagen immobiliser

Hello Lilas 1998,

Earth drain possible cause

I run a G500 and  found that after 3 days of inactivity the battery was flat.

I spoke to a pal and he recommended I check for an earth drain.

Disconect  the two terminals on the battery then connect a bulb to the negative earth of the battery And the negative lead coming from the "g". If the bulb lights up you are powering up an accessory while the vehicle is laid up. Of course if you charge the battery and then disconect the earth terminal you should come back to a full  battery .

Hope this helps,

Regards,

Morpheus.

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Sun, 02/10/2016 - 23:27
#2
Arnie
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Re: G wagen immobiliser

I think the question was about not being able to start the car with a a charged battery and new starter motor?

What year and model is the G Wagen?

 

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Tue, 04/10/2016 - 09:51
#3
Lilas1998
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Re: G wagen immobiliser
Many thanks. Have a good day.
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Tue, 04/10/2016 - 09:53
#4
Lilas1998
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Re: G wagen immobiliser
K Reg. Many thanks
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Tue, 04/10/2016 - 21:26
#5
Arnie
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Re: G wagen immobiliser

A K-reg vehicle would not have had a factory-fitted immobiliser. Many vehicles, however, were fitted with Mercedes Dealer (Scorpion) alarm systems. If you have such an alarm, it will have an immobiliser circuit on the ignition and starter circuits. This can be by-passed

See here:

https://web.archive.org/web/20050307172432/http://www.scorpionalarms.com/install_manuals/838fitting.pdf

 

 

The violet/Black  wire and the Yellow/Red wires at the end of the long connector plug are the starter and ignition respectively.

 

First, urn-off alarm by inserting the tubular alarm key in the top of the alarm unit, under the rubber boot, and rotating it. Usually the alarm unit will be under the bonnet, possibly on the bulkhead.

 

Then, disconnect  the long connector and bridge the relevant two pairs of wires in the connector plug. This will eliminate the alarm from the starting system.

 

You can do this as a quick test to take the alarm/immobiliser out of the system.

 

 

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