Thanks to everyone for the helping me determining if the inadvertent sounding of my factory alarm was due to a faulty tow sensor. Apparently I don't have one but my alarm continues to go off sometimes (too often)for no apparent reason. Has anyone experienced such a problem with their factory alarm systems.
Should I disconnect the system and forget about and install an after market system?
Again my car is a 1987 190E 2.6 .
If knowledge is addictive this site is a perfect example. I can't stay away from it for helpful advice and information.

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72 350SL #69
73 450SL Parts Car?
78 450sl Parts Car
79 450SLC - Sold
1985 280sl
87 190E 2.6 - Donated
90 300E-Junked
97 E420

Does the front doors and the trunk arm and disarm the factory system consistantly. It is important that all three work properly and if one doesn't then I would disconnect that switch and check the wiring in that door or in the trunk. I mentioned before I have seen this exact problem and it was caused by wires in the rt door were grounding out setting the alarm intermittently. The problem cannot be a sensor as the sensor do not set the alarm and in order for the alarm to false it first has to be set. The thing that is weird about the early factory alarm is that it can arm even if the car is running. There is no ignition kill so it won't stop the car from starting or kill it when it is running. I think you can lick the problem if you go about it as I have outlined.

Scott@lajollaaudio

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The Mercedes Specialists Since 1986

Scott,
Thanks for the reply and troubleshooting tips.
I have discovered that the rt front door locks and unlocks the car but does not arm or disarm the alarm system. It's getting dark here in Boston now but I will be removing the door panel and checking the wiring as suggested tomorrow, weather permitting. I'll let you know how I make out.

__________________
72 350SL #69
73 450SL Parts Car?
78 450sl Parts Car
79 450SLC - Sold
1985 280sl
87 190E 2.6 - Donated
90 300E-Junked
97 E420

Remember, there is an oval plastic hole plug in the back end of the door below the level of the handle. This can be removed and there is a three prong plug for the wiring going to the switch in the lock cylinder. You can have a quick look through this hole to see the wiring without taking the door panel off.

Good luck! I know you can find the problem!

Scott@lajollaaudio

__________________
The Mercedes Specialists Since 1986