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Discussion Starter #1 (Edited)
Stuck Relay? Battery Drain

:confused:

I have a battery drain and subsequent starting problem, that I BELIEVE is being caused by a component mounted in the right rear quarter panel. With engine off and keys out, there is a regular clicking sound emanating from the area in question. At the same time, the trunk lights are pulsating dim to bright.

I've read about trunk light switch issues? Is this the cause? Whats the clicking sound, related?

I should add that initial problem was a flickering in the Altnator light - very intermittent, followed by a dead battery. Took to my local to do battery and alternator test, which were 'fine.' Could be intermittent Alternator issue, low battery, cold weather = no start and unrelated issue in rear.

The car is an 96 S500 Coupe

I'd love to sort this myself this weekend...
 

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W221 & Audio Moderator
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I am not familiar with the 96 S500; you posted in the W220 forum, and your car is a W140. I am relocating this question to the W140 forum.

If this were occurring on a W220, I would suspect that your alarm system battery was extremely low, and that was causing the clicking and the flashing of your lights - which, over time, would drain your battery. In the W220 the alarm has its own battery, and it is replaced by replacing the entire alarm horn section. Bt that's a guess.

I hope someone on the W220 forum can provide the answer.
 

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:confused:

I have a battery drain and subsequent starting problem, that I BELIEVE is being caused by a component mounted in the right rear quarter panel. With engine off and keys out, there is a regular clicking sound emanating from the area in question. At the same time, the trunk lights are pulsating dim to bright.

I've read about trunk light switch issues? Is this the cause? Whats the clicking sound, related?

I should add that initial problem was a flickering in the Altnator light - very intermittent, followed by a dead battery. Took to my local to do battery and alternator test, which were 'fine.' Could be intermittent Alternator issue, low battery, cold weather = no start and unrelated issue in rear.

The car is an 96 S500 Coupe

I'd love to sort this myself this weekend...
I can't pinpoint the issue, but I think if I were having this problem, I'd pull fuses one-by-one until the clicking stopped in order to identify the circuit that is causing it.

Brett
 

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Discussion Starter #4 (Edited)
Thanks for moving this to the right forum, I knew it was a W140 and THOUGHT I was in the right forum, dunno what happened. User error, no doubt.

Well, situation has changed too, clicking had stopped when I went out to do exactly that as mentioned above, took a break to deal w family and then got a jump. Car would now crank and catch no problem, but would not run, stalled immediately. I guess battery completely dead?

Also, when the clicking and trunk light was situation was happening, it was only the trunk lights inside the trunk, not all of them like with the alarm...fwiw.

I guess I'll see if the clicking happens again and start with that.

Again, all thoughts greatly appreciated.
 

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I would say that the reg pack on the alternator is at fault, this will flatten your battery over night, easy to change and not expensive
 
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