Alarm randomly going off 98 S420
02-01-2016, 03:31 PM
#1
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1998 S420
Alarm randomly going off 98 S420
Last night I was awoken by a horn going off. Turns out it was my 98 S420. It had never done this before. The power locks did stop working about a month ago, so I have been locking drivers door with the key, but like I said this is the first alarm issue. Also there was quite a rain storm when this happened the first time.
I went out unlocked door and it stopped. I re-locked door, and about 10 minutes later alarm went off again. Did the same thing a third time, by this time the rain had stopped so I dont think rain was a factor. The third time I left the car unlocked and it did not do it the rest of the night.
I re-locked car today, and so far, no alarm. I looked for a fuse, no luck. All I found was a 25 amp in trunk that said security, and rear headrests. I looked in manual and was surprised this was the first car I remember with no fuse diagram in manual. Does anyone know correct fuse to pull to prevent this from happening again, or if this is a known problem??
I went out unlocked door and it stopped. I re-locked door, and about 10 minutes later alarm went off again. Did the same thing a third time, by this time the rain had stopped so I dont think rain was a factor. The third time I left the car unlocked and it did not do it the rest of the night.
I re-locked car today, and so far, no alarm. I looked for a fuse, no luck. All I found was a 25 amp in trunk that said security, and rear headrests. I looked in manual and was surprised this was the first car I remember with no fuse diagram in manual. Does anyone know correct fuse to pull to prevent this from happening again, or if this is a known problem??
02-02-2016, 03:18 PM
#2
Out Of Control!!
The anti theft and central locking system is extreamly complicated with many switches, sensors and fuses and to start pulling fuses that are used by many systems you may wind up loosing many different features.
Your best bet is find a garage that has the ability to read MB chassis fault codes and correct the central locking\anti theft system---or drive it till it drops!!
Your best bet is find a garage that has the ability to read MB chassis fault codes and correct the central locking\anti theft system---or drive it till it drops!!
02-02-2016, 03:28 PM
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1998 S420
The anti theft and central locking system is extreamly complicated with many switches, sensors and fuses and to start pulling fuses that are used by many systems you may wind up loosing many different features.
Your best bet is find a garage that has the ability to read MB chassis fault codes and correct the central locking\anti theft system---or drive it till it drops!!
Your best bet is find a garage that has the ability to read MB chassis fault codes and correct the central locking\anti theft system---or drive it till it drops!!
02-08-2016, 10:18 AM
#4
Super Member
Unsure how long you have had the car, may be a minor issue (battery, frayed wire short, etc.). If you have had the car for many years have the battery checked, if you recently purchased the car take it to a Mercedes Mechanic (independent or dealer) to have it checked out. The w140 is a pretty reliable car, but at 18 years you should expect maintenance issues including wire deterioration as part of the normal "wear" in hot climates.
