Z4M Completely Dead - no lights etc

[xxrb86]

Hi guys,

Not been driving the Z4M with lockdown, work from home etc

Usually keep it in garage on battery tender - no issues.

While ago it ended up off the tender - and battery has died - got it on a CTEK and ‘repair’ cycle - it’s proper dead (red triangle warning symbol - multiple attempts)

Have since tried an old spare battery in it - charges fine - multimeter confirms 12V - and car still ‘dead’ - like no battery - no lights, no radio, turn key - complete silence - no signs of life.

Tried lithium ion battery booster (a jump starter - he worked great before - no signs of life

Connected up battery terminals with and without battery to battery maintainer - no signs of life

Got smart - took cover off nearby battery fuse box thing - inadvertently discovered the ‘mega fuse’ and 40A fuse - checked with multi meter - shows voltage - shows contiunity across fuses

Started googling - hacked apart plastic cover on terminal (doh) but no - I’ve not blown the pyronetic on the terminal - and continuity and voltage checks should of spares me the job lol

Then remembered jump terminals under bonnet - and tried battery booster - again - not a sausage

Now desperate lol - any ideas???? :x

 

[xxrb86]

To be clear - battery terminals under bonnet shows 12V! And still nothing with key or any accessories etc

Only ‘strange’ thing to happen recently was guy cleaned drive and it sprayed crap all under door and onto car

Wife gave it a rub down… (the car) and said it ‘wasn’t that bad’

 

[buzyg]

Have you been through the fuse box and checked them?

Have you actually tried putting a new battery in?

To start the S54 you need a fair old wack.. I have jump sated mine a few times after dead batteries. I use the wife's mx5 1.8.

Where about are you based?

Oh and welcome to the forum.

 

[Mister T]

Sounds like an issue with the battery safety terminal, I'd check that first (it's the black box with a small black wire going to it on the positive battery cable)

 

[enuff_zed]

Sounds like an issue with the battery safety terminal, I'd check that first (it's the black box with a small black wire going to it on the positive battery cable)

I think he's done that?

Started googling - hacked apart plastic cover on terminal (doh) but no - I’ve not blown the pyronetic on the terminal - and continuity and voltage checks should of spares me the job lo

Think I'd be popping a new battery on there first to at least rule that out.

 

[Mr Tidy]

The battery in my MC was so flat last year when I unlocked it the alarm started going off!

But it fired up OK using a jumper pack on the under-bonnet terminals - even if I did get 3 amber warning lights.

A new battery might well be a good starting point anyway because if it has been flat for any length of time it will be past saving, but good luck getting it sorted.

And welcome to the forum - just be aware we like to see photos of members' cars!