Last month I purchased a 1987 260E with just 80k miles. After minor cosmetics, we have a great car considering the $2500 purchase price. During my last trip in the car, I noticed that a tick sound started coming from the passenger side front interior, sounds like it is coming from under the glove box. It sounds like a relay? ticking similar to the sound that the blinkers make. Once you shut the car off, it still DOES NOT stop. The ony way I can get the ticking to stop is to disconnect the battery. I have not noticed anyting that does not work properly, making this a bit of a mystery. Before I tear into the interior, I wanted to ask anyone if they had any thoughts as to what might be ticking? Thanks for any help.
Thanks - actually turns out to be a black box under the mat
Thanks for the reply. I located what is ticking, it is a black box that says becker on it. I wonder if it is part of the security system associated with the original radio?
It has two wiring harnesses , one of which is unplugged. If I plug it in when it is ticking, the headlights and flashers start going off. Any idea if I can just remove the box all together? Im assuming not since the prev owner left it in after upgrading the stereo.
Hi Erik, yes that's the ATA System (AKA Anti-Theft Alarm System), identified as N26 in the service manual. It is not directly related to your radio (original or upgrade). It probably was unplugged because the previous owner got tired of it going off by itself. I've read that some owners just disconnect them because they frequently seem to misbehave. It is perfectly safe to completely remove the unit and it won't affect your car otherwise.
But following in MBs reputation for high quality components, I'll say your problem might simply be in the ATA switches that are located in both front doors and are the ones that actually turn on or off your ATA system when you turn the key to open or close either door. Because of their somewhat exposed location, these tend to get dirty. Also look for any stuck or shorted hood, door or trunk switches. If you're planning on keeping the system make sure to check on all of these switches before discarding the Becker module. The system also monitors (and trips the alarm if it is activated) when the radio, the headlamps, or some other items are turned on, or the brake pedal is pushed (stop lights turn on). When the alarm is tripped it flashes the lights and sounds the horn that is mounted on the left side fender of the engine compartment. It is also possible that the module itself is bad and needs to be replaced, but if that's the case, and a replacement unit usually won't come cheap, you're probably better off installing an aftermarket alarm system that will cost less and give you more conveniences like remote control, etc.
Incidently I'm looking for a Becker ATA Module myself, it was missing on my car when I bought it. If I manage to get hold of one at a decent price, I'll definitively would give it a try to restore the original ATA.
Good luck and let me know if I can be of any other help.