I am considering installing the top of the line Crimestopper Informer alarm on my 420. It has all sorts of bells and whistles on it including keyless entry and remote start. It has its own siren too. Could I install this w/ no problem? Couldn't I just disconnect the factory alarm and start with a clean sheet so to speak?
www.crimestopper.com

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'86 420SE Euro
904 Midnight Blue, Gray Velour
Dad bought it new, now I own it.

"A Mercedes-Benz is like a fine wine, it only gets better with age."

You can disable the factory alarm by disconnecting the two plugs. That should leave you with a fairly clean sheet. In fact, most of the connections you need will be collected in the alarm box area. You can even use the factory alarm horn instead of that annoying multi tone siren that no one pays attention to anyway.

Sixto
91 300SE
87 300SDL
81 300SD

Isn't the alarm box area in the passenger side footwell somewhere?

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'86 420SE Euro
904 Midnight Blue, Gray Velour
Dad bought it new, now I own it.

"A Mercedes-Benz is like a fine wine, it only gets better with age."

"Check the alarm controller in the passenger footwell. Lift the mat and carpeting and remove the board. There should be an approx. 6" x 10" box with 2 long connectors with about 12 pins each."

That's what the guy said. Wait, it was me

Sixto
91 300SE
87 300SDL
81 300SD

420,

did you have to perform that surgery on the circuit board? i wanted to try this but that part sort of intimidated me. i'm also wondering if anyone has ever attempted this on a W124. there is an alternative method using Crutchfield components but it seems somewhat more complicated. i'm almost sure the connections are available in the w124 trunk because you can lock / arm from there...

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joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
http://banners.wunderground.com/bann...L/Key_West.gif

jsmith wrote.

"did you have to perform that surgery on the circuit board?"

Yep. I wasn't too difficult to do but I do have some soldering experience from working on RC cars in the past. It can be frustrating so I'd get some practice in before you try this.

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73 220D
08 997 C2S
03 Jetta wagon TDi

What do you guys mean by surgery and soldering? Those to wires and connectors don't just pop off to disable the factory alarm?

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'86 420SE Euro
904 Midnight Blue, Gray Velour
Dad bought it new, now I own it.

"A Mercedes-Benz is like a fine wine, it only gets better with age."

mbtjc,

we are dicussing the adaptation of the JCWhitney Valiant system for W126 & possibly a W124. if you read the step by step procedure in that link ath beginning of the thread, you'll see that you have to open up the Vaiant unit and do some minor soldering / modification to the printed circuit board.

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joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
http://banners.wunderground.com/bann...L/Key_West.gif

this sounds like a nice to have feature but it really just gave me a lot of aggravation in the family van. i would start up the engine, which would then cause the doors to lock. whoever was outside would then try to open the door while i was trying to unlock the door which of course is mutually exclusive. repeat a couple of times and it gets really annoying. this went on until one day i got really tired of it and disabled that feature...

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joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
http://banners.wunderground.com/bann...L/Key_West.gif

could you rig this up on a pre-86 model with an electric pump? i have an 83 300SD that i would love to rig up keyless to, dont care about the alarm. Car doesn't have a factory alarm. If i could install myself for 40 bucks i'd do it over the summer!!! thanks
Ryan

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83 300SD.......sold
96 integra SE....sold
99 a4 quattro....sold
2001 IS300.......sold
2002 330i.........current.
2004 highlander limited....current.

Ryan,

The procedure described at the begining of the thread will work on any US W126. You don't have to worry about the factory alarm since your 83 doesn't have a factory alarm.

Sixto
91 300SE
87 300SDL
81 300SD (on ebay)

sixto,
you know if this has been done on a w124 successfully? the crutchfield solution is tried and tested and even at double the price of the jcwhitney solution it is still a good deal...

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joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
http://banners.wunderground.com/bann...L/Key_West.gif

I don't know if anyone's done this on a W124. I can't imagine it would be any different. the only real difference between the W124 and W126 is that the W124 pump is under the rear seat.

I prefer the Crutchfield solution myself since I can't solder to save my life and the benefit of Crutchfield support seems to be a worth the extra money.

Sixto
91 300SE
87 300SDL
81 300SD (on ebay)

I should add that I did not find Crutchfield's support to be that good - it required many calls before they figured out they had sent me the wrong relay connector. The way 'they' figured it out is when they sent me the wiring schematic and I realized I had the wrong connector. I did get a full refund on the part, though.

This does trsanlate into a waste of time and distrust of the vendor.

Eventually, I made my own relay connector by following the schematic and bench testing the whole thing with a 12v supply. All that bending over into the trunk/pump area gets really tedious....

I bought the third relay and socket for the horn and the diodes for the flashing lights (you only have to connect the rear ones to get all four flashing) at a local electronics shop. Very inexpensive.

ok, i pieced together all the information and realized that all that was really involved to do the keyless part of it was to send power into the unit and the to figure out which wire would do the lock / unlock. apparently on the w124 it's that blue wire that's connected to the vacuum pump. i could brobably go in the trunk but i hate having to do trial and error since nobody seems to know about the connections back there for the w124. i picked up a jcwhtney keyless entry that says it has built in relays and works with vacuum pump systems. i will be sure to post my results...

__________________
joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
http://banners.wunderground.com/bann...L/Key_West.gif