2003 E39 - Battery/Electrical Problem

[goldschlager1]

Hello - similar post to - http://www.bimmerwerkz.com/forum/5-s...nal-59294.html

Drove car to store, came out after ten minutes, turned off alarm and all electrical died - no start, no dash lights, no radio, no powerlocks, etc. After research online I found above post, opened trunk lid (using manual override), and jiggled red cable from battery terminal.... power came back and car started fine.

My question is - what is the diagnosis of the problem and what actions should I take to prevent from occurring again?

Thanks in advance for your advice.

[witeshark]

Is there any sign of corrosion or dirt on the battery terminal?

[marti5]

Tighten you battery terminals up....

[goldschlager1]

No corrosion - happened again this AM - had to have a neighbor jiggle the red battery cable while I started the car (otherwise power would cut back out as soon as I tried to start the car after restoring the power by "jiggling" myself). Terminal seemed tight but will tighten later today. From other posts elsewhere tightening didn't solve the problem but I'll keep my fingers crossed

[marti5]

It could possibly be the battery internals have corroded away under the + post thats why a jiggle does it......so basically you have a dead cell or an internal short, so new battery required.