Battery dead and can't jump

[S65Tom]

Hey all thanks for stopping by. Little history of car, dead battery last year found almost up to the top of battery with "rust" water stains. Replaced battery but didn't remedy problem fast enough and died again 4 or 5 months later. The positive cable bulletin was addressed already before first death. Winter came and didn't worry because it's not my primary car. Nice out today so decided I would try and jump it to get to battery, no luck, wouldn't unlock trunk actuator, check 4 fuses that look like 4 locks and all good. Car is an 11 e90m with non fold down rear seats. Took lower seat cushion off and 2 t-50 bolts out but cannot get to emergency handle in trunk. Any suggestions would be greatly appreciated. Thanks, sorry for winded question

[msan]

Can you open the hood and power the car through the positive post in the left side of the engine bay?

[S65Tom]

Yeah i tried that by opening car with actual key. Left it hooked to my other car running for like 15 minutes and would not turn on an interior light even.

[amrazM]

That box on top your battery in the trunk is likely failing.


Do you have ski bag pass through?

[S65Tom]

I do not have a pass through either. That $500 dollar split seat option is all of a sudden looking useful. I probably need to get it towed somewhere but it's fairly low on kw clubsports with a gt4 lip so that's going to be a challenge too

[mapster37]

if fuse box on top of battery checks out contine here: rust line on battery is a sign there was water in battery compartment. check positive cable connections under battery, could be rusted/broken off.
make sure to fix source of water intrusion.....

[S65Tom]

Current problem is figuring out how to get into trunk at all, lock cylinder fuses were good but with jumped to another running car could not pop trunk and no lights

[pbonsalb]

Try jumping with an added temporary ground. The main ground under the engine rots over time. Rig something up under the hood temporarily. An extra set of jump cables used as chassis ground to motor is fine for this test.

[S65Tom]

Thanks will try that tomorrow, tried a couple different spots under the hood to no avail

[pbonsalb]

Hard to find good ground spots on the block to clamp to. Worth a try. This was my problem last year with no start (and I changed battery and starter and alternator before figuring it out).

If nothing else, by powering up there you should be able to get the trunk open. Unless you have the bigger problem you are worried about — a wiring failure somewhere inbetween.

[S65Tom]

Yeah hope not a wire issue from trunk, may have to pull diagram and jump 12v to the trunk actuator direct in the harness by backseat haha

[pbonsalb]

I have fold down seats and ski pass. Have reached inbthere before for trunk release. Not sure how fixed back seat backs are removed.

[S65Tom]

I think it's a release spring in the upper shelf but you need trunk access to get to it, which is where I fail