I am new member of this forum and I currently own a '89 300E and I was wondering if any one has removed their factory radio? If so, has your factory alarm continued to function? Currently, my after market radio works great, but I no longer have a functioning alarm! I had to disconnect the alarm form the passenger foot well because the car thought the radio was stolen. Has anyone else had this problem and if so what was the fix. Please help [V]
Hey, I am glad someone brought this topic up. I have an 1987 300TD, equipped with a non-functioning factory alarm. It does not have a stock radio, so this might be a really good clue. I have wiring diagrams for this (and your) vehicle.
Since this is my first E-class, and since it did not come with a Owner's Manual, I was waiting to get some more information about said system so I could better understand how it is supposed to behave.
How does one know it is armed? How abount when it is going off (assuming the horn is disconnected)? How does one go about "forcing" the alarm to trip.
Looking in the "Electrical Troubleshooting Manual" for W124 1986-1992, Pin 12 on the "Anti-Theft Alarm Control Unit" senses when the radio is removed. This is a Brown wire with a Blue stripe. It is unclear to me if this input should have either +12 when the radio is installed, or should be to ground. I am guessing to ground.
N26 - the Anti-Theft Alarm Control Unit is apparently located behind the front passenger carpet, on the right side, opposite the seat.
You got me interested, acmerocksusa, so I pulled the carpet up to have a look at N26 on my 1987 300TD. Sure enough, both wiring harnesses going to it are unplugged. Tomorrow, I'll plug them in and see what happens. You can bet I'll have to focus on defeating the radio removal detection circuit. Hopefully, someone here can confirm if it is supposed to be grounded or not. I've got the wiring diagram from the "Electrical Troubleshooting" guide, but cannot ascertain how it should be defeated.
I plugged her in and tested her, today. I rolled the driver-side window down. Locked the car with the key, unlocked the door using the pull, opened the door, and bingo, the alarm went off. Although, I do not have a factory radio, it did NOT go off following the arming. In fact, it seems to behave just fine. I will test that pin 12 to see if it is grounded and let you know. Perhaps when my radio was installed, it was defeated properly. I guess time will tell me WHY the anti-theft was disconnected to being with.
PiterSchloss,
I remember trying to ground that brown/ blue cable and after doing so the alarm continued go off. Will it be too much ask if you can let me know how you radio is connected and how the wires are terminated to your console?
I left my anti-theft unit hooked up, it seemed to work okay. I tested pin 12 and it was, in fact, grounded. However, the car came with the aftermarket radio, and I have not bothered to pull it. It might be some work. Is this enough information? Maybe there is another issue at play, here.
Linear Mode
