My 355 has suddenly started to drain its battery. Twice in a row, the battery got emptied completely in a couple of days in the garage. The battery is less than a year old an otherwise fine. It recharged fine after two apparent slow discharges which are normally quite hard on lead-acid batteries. I use the switch when the car is left alone for an extended period, but never experienced anything of that magnitude, so something must have gone wrong and created leakage current (the charger plateaus at 1.5A after a night of charging). What should I look for ? PS all obvious current consumers were off, radio, roof lights, etc ...
I would check the alarm, It drains a lot of current. Second, I use a battery tender on my 355 all the time it is not running. Mike
Thanks. What would "checking the alarm" entail ? I understand the rationale for a battery charger, but there must be another problem. I've had the car for 4y & 25'000km and something has suddenly gone wrong 2w ago.
mac is right. alarm is the #1 electrical consumer eventhough car is sittting. you also can do this>>> i have seen it >>> go to the car at night and look from the side at rear to fron between the door and qtr panel. you might able to see the door opening lights stays on some time which drain battery in one night easily. if its that then replace the door switch nothing else. at night you will able to see more thing which is hard to see in daylight.
You might also want to check to see if the ignition switch light is staying on. It's supposed to be on a 15 second timer, it's possible that the relay isn't shutting it off. I'm assuming that the 355 system is the same as the 348.
Good tip, but it's not the door switches, both are off and turn on only well after the doors have been opened. I also listened to the CD changer but it does not seem to be stuck cycling through the discs. Still don't understand what could make my alarm suddenly draw much more current, neither how I can check it. Re: ignition switch light, what light do you refer to ? I scrutinized the car in the dark and there's no sign of any light, other than the alarm LED starting to blink after a couple of minutes as it should.
Again, I'm not sure if the 355 system is the same as the 348. Look in your Owners Handbook in the section about the dome lights and see if it mentions an ignition switch light. I just checked my 348 to be sure. There is a TINY little light inside the slot for the key in the ignition switch. When you open the door, the dome light and the ignition switch light come on. When you close the door, the dome light goes out right away, but the ignition switch light stays on for 15 seconds, then goes out. If you listen closely, you can hear the relay click when it shuts the light out. I had to lie across the seat and cup my hand around the switch in order to see the light during the daytime, but it's there. I have no idea how long the light would have to burn before it ran the battery down.
Is your alarm light flashing normally when set? If not (it is continous red), then you need to replace the rechargeable batteries in the alarm. This could be the cause of your excessive battery draw.
Yes, key off the ignition lock, and alarm blinks as it should. One thing I noticed last night is that, more than 10 minutes after stopping the car, there was a periodic noise in the rear left engine compartment, sounded like an electric pump, cycling about 15s on, 20s off, etc ... for a while. Checked again later in the evening, no noise anymore. I guess I will have to check the current running through the fuses one by one, but if there is an intermittent consumer, I could well miss it.
Measured the current at all fuses in the front left wing compartment and in the passenger footwell: all are at a couple mA (the noise level of the ampmeter), while it takes about 24 hours to drain the battery to a stage where the F1 pump barely runs (and the starter doesn't). The battery holds charge fine for more than 2w if I switch the master ignition switch off. Does anyone have a hint on how to narrow down the problem ?
