brownboy

I'll be out of town for about 3 weeks and have left the car sitting that long in the past without having immediate battery problems but both batteries seem to go out every 2 years so perhaps it's not a good idea. I can't easily put a battery tender on it since I'm in a high rise downtown.

I was considering disconnecting the rear battery while I'm gone. But what's the proper procedure when you have the power trunk closer? I left the car unlocked with the top up and tried to open the trunk with the mechanical key but turning it either direction didn't actually pop the lock. I had to grab the handle which of course led to the automatic opener kicking in.

Should I let that happen, disconnect the rear battery and close the trunk lid manually? Then lock the doors manually? Normally I wouldn't would worry about doing this but I've learned that you want to follow procedures with this car lol.

Rudeney

FYI, when using the mechanical key to open the trunk, you have to turn it to the right, old it there, then squeeze the handle. As for locking after disconnecting the battery, just close the trunk (it should latch manually), lock the passenger door from inside, and use the mechanical key to lock the driver's door.

brownboy

Thanks Rudeney! I will follow this procedure.

brownboy

Did a quick test of this but forgot about the window adjustment that can't occur when the battery is disconnected.

After reconnecting the battery and starting the car I had to raise and lower the windows twice to get them to reset. I also got the big yellow exclamation point in the gauge cluster. The music stored on the hard drive didn't show up either.

Thankfully after a few minutes of driving everything was back to normal though I may have lost the garage door programming. I removed just the negative terminal battery cable.

brownboy

I'm leaving on another long trip and disconnected the battery in the trunk and closed the lid. But I can't open it with the mechanical key. I thought inserting it, turning it, and then pulling the handle would release it manually but it does not.

Does anyone have any suggestions on how to open the trunk with the battery disconnected? Perhaps last time I did this I didn't close the trunk completely after disconnecting the battery.

brownboy

If I supply 12V through the cigarette lighter do you think that will be enough to power the trunk release? Or should I try to power the trunk opener directly from the fuse? According to: https://benzbits.com/R230/Fuses/ it looks like it's on F9 under the hood with a 40A fuse. 40A is more than I can inject into the cigarette lighter I believe.

Tom Manning

If you have the front battery connected then the car will start and run on that. Then you can open the boot normally.

But does the key insert and turn? With the handle pressed up and the key turned, it should open. If not I can only imagine that the lock is faulty.

Tom Manning

If key doesn't turn then it almost certainly just needs lubrication in the tumbler and lock.

brownboy

That worked thank you Tom! The front battery was still connected. I wasn't sure if something would be damaged if I started the car with the rear battery disconnected or if that would even allow the power trunk to operate but it did after a delay.

I have 2 keys and the mechanical keys from both of them go into the lock and turn either direction smoothly but operating the handle does nothing regardless of the position of the key (tried at the 10 o'clock position of course). I also tried spraying some WD40 into the lock.

I guess my lock is faulty, possibly in the manner shown in this video:

Tom Manning

Good job. The system allows for the car to run on the front battery as an emergency, so you have brakes and other essentials.

Probably someone repaired the leaking boot lock once and didn't reconnect the lock properly. Take off the boot liner and the issue might be apparent.

brownboy

I had a shop replace the PSE pump a few years ago so perhaps something got messed up then. I'll take myself and also mention it to the shop next time I'm back there. Thanks Tom!