Re: BMW E46: dead battery, locked trunk // Fix: good voltage to actuator

My experience with a trunk mounted battery in a 2002 (ish)  BMW X5. Absolutely would not start with the dead battery connected and with a fresh battery as a jumper. Removed the dead battery and connected fresh battery and it fired straight up.

Look for where the cable runs to FROM the battery. It's gotta connect somewhere in the front of the car (starter lug or even just at the jumper lug?). disconnect the trunk mounted battery from there and hook your fresh battery up to that same connection point using very good jumper cables and try again.

That's all I got.

Re: BMW E46: dead battery, locked trunk // Fix: good voltage to actuator

Great suggestion - thanks. In prep for building a Lemons, last year I pulled several BMW cables at my local PnP, so I should be able to find out where this comes out in the front.

Still won't be able to get in the trunk without the master key, though (BMW p-i-t-a).

The good thing is it can stay where it is for a while. But I'll likely also need to disconnect the cable to get into the trunk if the relay is voltage dependent.

Re: BMW E46: dead battery, locked trunk // Fix: good voltage to actuator

Just checked the junkyard price sheet.  Trunk lid $41, trunk lid with hinges $45.

Tri-Lamb Motorsports ‘87 528e

Re: BMW E46: dead battery, locked trunk // Fix: good voltage to actuator

Ta-daaa!

https://i.postimg.cc/JzMJqsZj/20201103-152036.jpg

Solution:
1. Power on, with a _good_ voltage./1
2. Set power door locks as "unlocked"./2
3. Hope to God the trunk key cylinder slot is vertical .:. unlocked from the perspective of the owner - which it already was; so I apparently don't _need_ a master key.
4. Use the button under the trunk overhang trim to unlock the trunk - yay!/3


Ok, so the BMW fans are quietly amused at my travails, but they must consider them to be some sort of 'initiation' to the joys(?) of Bimmership, right?


/1: yesterday I left a large capacity battery connected by jumper cables to the charging points in the engine compartment for almost two hours, while I emptied the trunk through the access panel. When I left, the last thing I did was check the panel lights by turning on the key; there was just a dim illumination of one light on the dash, but that was much better then before. I think the battery took just a little charge as the batteries balanced themselves - which is a good sign. I again charged up the jump battery last night, so I started with a good jump battery today. I connected it to the car, and the lights are much brighter now; so I'm hoping the voltage is close to correct.
/2: When it was running last week, I know I set the doors to "unlocked", as all the pins popped up. Today, the door lock pins didn't move at all when I used the switch from unlock, to lock, to unlock again, twice.
/3: I know I tried this button last week after I unlocked the doors. Not sure if the car was running. Also not sure if the car was energized with the key, though. _That_ might be the ticket. I'll verify and clarify tomorrow.

Re: BMW E46: dead battery, locked trunk // Fix: good voltage to actuator

Final:
With the battery charged and the doors unlocked, I didn't even need the key turned in the ignition for the button on the trunk lid to unlock the trunk.

31 (edited by bobnowoc 2020-11-20 10:44 AM)

Re: BMW E46: dead battery, locked trunk // Fix: good voltage to actuator

Horray!  I am so happy for you.
We cant wait to meet you on the track!

(Margret, take a note.  Do not buy Lemons quality BMW.)

Captain
1996 Crown Vic. #55
Team Racing Cosmo
On MuchoMacho tires

Re: BMW E46: dead battery, locked trunk // Fix: good voltage to actuator

Thanks; looking forward to it also.

It _has_ been fun in the parking lot. I'll eventually get a clean title, put new tires and brakes on it, and drive it on the road.

And the check engine light has gone out.