Disabling the Alarm
on the 1993 300E (W124)
by latief
1/19/10
This is my write-up for those people who have a funky alarm like mine. I have been putting this off for a while now, but decided to tackle it since I had the cluster out for some other work....
Problem: Alarm goes-on when i unlock the car from the driver's door.
Solution: Disable the alarm. You can try to fix it, but i understand it will cost a fortune, and too much of a headache for me. Besides, I don't need it !!!
Step 1: Disconnect the car battery so that the alarm does not go-off, or you get hit by an airbag while removing the cluster.
Step 2: Locate the alarm. In my case, it is under the passenger's feet. remove the floor mat and the foam-backed carpet piece. Unbolt the bolt holding the black plate in place. The alarm is the black box on the left with two big plugs going into it.
Step 3: Unplug those big plugs. On pre 1993 cars, this should be sufficient to disable the car. Not the case though for 1993+ cars as they have an immobilizer feature that is triggered when the alarm is disabled. so my car would not start after unplugging those two plugs.
Step 4: You have to find the relay with the name k38. It is located under the instrument cluster. by jumpering this relay, you will be able to by-pass the immobilizer, and have a fully functional car without the alarm. So proceed to removing the instrument cluster as seen below, that is the nastiest part of the job as that thing is tricky....in the picture, the cluster is removed.
Step 5: Locate the k38 relay. it is in the upper left corner of the cluster space. it is shiny silver in color on my car....pull it out by hand- easy!!
Step 6: In order to bypass the immobilizer feature, you need to jumper pins 30 and 87 on the relay, see the picture below. I ran a copper wire between the two pins. Make sure the wire is as flat as possible so that the relay seats properly.
Step 7: Put the relay back in place. connect the battery without tightening the terminal. try to start the car, if it starts, remove battery terminal and install cluster.
Step 8: Tighten battery terminal, and enjoy your car with no annoying alarm !!!!!
Easy job over all. the hardest part was removing the cluster.....Good Luck, Thanks for the help with this guys!!!
Discuss this DIY here.
-latief
CategoryDiy
