URGENT! Factory alarm going off randomly! - PeachParts Mercedes-Benz Forum

TheDon · #1 03-30-2011, 10:58 PM

Help!!!!!

It's raining here in FL and the factory alarm in my cabriolet is randomly going off.. I removed fuse 9, I hope that is the fuse for that alarm.

But I poked around inside(no rear interior) no leaks in that area and the only other leak that I have is from what I think is the mirrors on both doors...

help!!!

Solid Snake · #2 03-30-2011, 11:20 PM

I had this problem once in my W126; if it's the same, remove the carpet from the passenger side and unscrew the cover for these relays in the footwell.

Should be a big black one making a ticking noise; unplug it. The problem with mine was that moisture got in there (long story) and was shorting something. I left the windows down and it didn't reoccur when I hooked it back up.

Hope this helps!

-Carlen

TheDon · #3 03-30-2011, 11:25 PM

I did some digging here and apparently the late w124 has a feature that disables the car while the alarm is triggered. So the cluster has to come out, jumper some relay and then I can unplug it.

I currently have the battery disconnected. I now have to get up stupid early to reconnect it, and move my car so my mom can bring my brother to work. Awesome.

86560SEL · #4 03-31-2011, 02:40 AM

Quote:

Originally Posted by Solid Snake

I had this problem once in my W126; if it's the same, remove the carpet from the passenger side and unscrew the cover for these relays in the footwell.

Should be a big black one making a ticking noise; unplug it. The problem with mine was that moisture got in there (long story) and was shorting something. I left the windows down and it didn't reoccur when I hooked it back up.

Hope this helps!

-Carlen

Oh yes, this happened once on my W126 about 2 years ago... for a week it did it like 3 different times. It finally stopped and not done it since. Strange, but yeah I heard that module/relay is in that passenger side kick panel... at least on the W126.

davidmash · #5 03-31-2011, 12:07 PM

My 201 was doing that and I ended up tightening the towing sensor thing under the back seat. It's that white canister that detects movement. You might want to check that out. If was storming and windy, that might be part of your problem. Just an idea.

TheDon · #6 03-31-2011, 12:10 PM

Quote:

Originally Posted by davidmash

My 201 was doing that and I ended up tightening the towing sensor thing under the back seat. It's that white canister that detects movement. You might want to check that out. If was storming and windy, that might be part of your problem. Just an idea.

IIRC that wonderful feature was done away with in 88. I have the entire rear interior out and there is no such a module that I can spot.

TheDon · #7 04-05-2011, 07:21 PM

The alarm is going off randomly again. It rained earlier today but everything is dry now. If I bump the car to the right of the handle on either side on the body the alarm will go off...

I guess I'm going to have to bypass the stupid alarm

JohnM. · #8 04-05-2011, 07:28 PM

Did you unhook the alarm control unit from the passenger footwell?

I didn't think the factory alarm had "movement" sensors. Just would go off if the door was unlocked by pulling up the knob, etc.

TheDon · #9 04-05-2011, 07:29 PM

the late w124 has an immobilize feature when the alarm sounds. I have to pull the cluster and jumper a relay so it won't immobilize itself.

JohnM. · #10 04-05-2011, 07:53 PM

Ah. So even with the control unit unplugged....the alarm is still going off "silently"?

TheDon · #11 04-05-2011, 08:02 PM

yeah and the car wont move. Found that info on another forum

Aquaticedge · #12 04-05-2011, 08:15 PM

Quote:

Originally Posted by TheDon

yeah and the car wont move. Found that info on another forum

found that out the other day too.. the hard way.

JohnM. · #13 04-05-2011, 08:53 PM

Just looking through my FSM. The Alarm control module on the cabriolet is actually "Behind convertible top hydraulic unit in trunk". Try locating that and unplugging it!