[W126 Coupe] Not Normal Battery Drain

[Vance Rowley]

The time of 30-60 seconds sounds like the same time a bad vac pump in the trunk will cycle, but you would hear it...Good luck.


OK, this is one to chew on. We have all heard of battery drains and the usual reasons for them. There's tons of info in the archives on the subject. Basically my 91 Euro560 has been fine when used on a daily bases, but has a horrible tendency to drain the battery if left standing for a week and sometimes just a few days. All the usual checks have been done and all appear fine including the battery and alternator, as well as the usual trunk light story and so on. 



However, one time when I thought I would have another try during a current draw test (meter between the battery and the terminal) with the test it was noticed that most of the time the current was well within the specifications that are listed and expected with the car in standby you might say (a matter of around 60 to 85ma). But every so often (not the same time period each time) the current flies up to around 6 Amps for about between 30 and 60 seconds, then goes back down to the normal expected current draw for seemingly no reason. This happens on a regular basis, but never exactly the same time in between. Sometimes it will take only about 3 minutes for the current to peak and other times it might take as long as 10 minutes.

This must have been going on now probably for around 5 years. This problem has never been solved and with the time period not being the same in between the peaks is a nightmare to find. If the 6 amp draw was there all the time, it would be a piece of cake by just removing the fuses until it disappears. Can you imagine how long it will take under these circumstances?

 

So my question is, has anyone else ever come up with these symptoms and found what it is that is drawing this 6 amps intermittently?

 

Regards,

Vance. 

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