Howto get into a dead battery car

[Ian B Walker]

I was tasked with getting into a W208 that had an abused boot lock and totally dead battery. Having asked questions here in the Forum I set about achieving todays task. This is a howto on how I managed to do it.

Remove the door foot strip by pulling upwards from the rear (more room for fingers)

Then remove the rubber door seal (pic not shown) by gentley pulling it off from the bottom. Next undo the screw on the inside kick panel and unclip the two body to panel clips that are or were under the door seal. Pull the kick panel backwards and put to one side.

Take out the carpet and reveal this. Then unbolt the three plastic nuts that hold it in position (10mm)

You will see this

What we are looking for is the item on the right hand side. There is a black cover over a nut, remove the cover (already done in the pic). This is the main battery cable from the battery to the engine. Attach your jump lead to this nut and an earth to any solid part of the car (I used the steering box).

Now you have power not only to the battery but all car elecrtics. In our case the boot popped open as we connected the cables. This may not work on every car but it most certainly does on a W208 CLK200

 

[GrahamC230K]

Excellent. A very useful guide.

 

[Flash]

Nice write up...

If went to a Stealership they would probably insist on "smashing" their way into the boot as well as charging their normal labour rates to add further insult to injury in addition to the damage...

 

[Ian B Walker]

I have to change the boot lock after sorting the starter motor, changing the gearbox and other minor tasks. So smashing my way in or about is not an option hahaha. More howto's on a W208 to come.

 

[silverarrow]

best way and quicker is to use the 12 volt cig lighter adapter
most car places sell them ie fast charge the dead batt
thats what the trade uses so my mate says

 

[Ian B Walker]

best way and quicker is to use the 12 volt cig lighter adapter
most car places sell them ie fast charge the dead batt
thats what the trade uses so my mate says

We tried that but the ciggy lighter is ignition managed and without power we could not turn the key.

 

[jaymanek]

have you bought this??

 

[Ian B Walker]

have you bought this??

No its Sil silv.... Dull Chrome. Seriously no I havent bought it. I have been asked to sort out a few issues with it.

 

[mickgrayson]

power

Hi Ian that bolt you accsessed from inside passes through the floor and attaches to the starter cable,it is covered by a push on plastic cover,this pulls off revealing a nut to which a jump cable can be connected.
Mine was corroded under there which gave me another repair job to do while replacing the clutch.

 

[miro]

What about injecting power into the 12V socket ?

 

[Ian B Walker]

Hi Ian that bolt you accsessed from inside passes through the floor and attaches to the starter cable,it is covered by a push on plastic cover,this pulls off revealing a nut to which a jump cable can be connected.
Mine was corroded under there which gave me another repair job to do while replacing the clutch.

Mick, I didnt crawl under the car to look for the nut you mentioned. However inside the car the terminal was covered by a plastic cover.

What about injecting power into the 12V socket ?

what 12v socket would this be?, interested for future reference.

 

[abbos]

Just a bolt on to Ian's post, this is exactly the same for a W202 however the box with the plastic cover is located at the back right hand side of the engine bay when facing the car.

Very handy to know.

 

[SilverSaloon]

We tried that but the ciggy lighter is ignition managed and without power we could not turn the key.

u could try connecting same ciggy lighter recharger unit to the always-live 12v power supply that goes to the radio - constant 12v....

 

[sjmaxwell]

I had a dead battery and a 'stuck' boot lock on my CLK 230K 2000 year. The Mondial guy came out and unscrewed a cap under the bonnet near the hinge on the nearside. From there he powered the car up and used the remote boot release.

I don't know if this is only on the 230K.

 

[grober]

12v option!

what 12v socket would this be?, interested for future reference.

think Miro means the auxilliary 12v socket found in lots of newer cars. In the new C class its found where the cigarette lighter was in the front console if the non smoking option is selected from factory or maybe a additional cost option ?? I have a feeling its still only "live" with the ignition switch in position 1 tho.

 

[fuzzer]

what 12v socket would this be?, interested for future reference.

think Miro means the auxilliary 12v socket found in lots of newer cars. In the new C class its found where the cigarette lighter was in the front console if the non smoking option is selected from factory or maybe a additional cost option ?? I have a feeling its still only "live" with the ignition switch in position 1 tho.

your right. the ciggy is a switch is ign sense.

Not sure about the older cars , but there is a battery terminal under the bonnet on my c class and 5 series ( had to jump the 5 series twice so i know it well )

 

[mchips]

If you have a 202 series, there is a good thread with pictures showing where things are located in the engine compartment:

http://www.club202.com/forums/showthread.php?s=&threadid=5771

 

[Birdman]

Nice write up...

If went to a Stealership they would probably insist on "smashing" their way into the boot as well as charging their normal labour rates to add further insult to injury in addition to the damage...

Can the dealer use eg. the STAR diagnostic interface to put volts into the system? Or jump start the system?

 

[Uky]

Et tu my CL

The same situation applies to the CL500 (C215). The battery is in the boot. The big junction is underneath the front passengers feets...

In order to open the boot lid, electronically, you will need 12Volts. And lots of current.

For CL's that has been around a guess is that the boot lid lock mechanism is corroded. (Thanks Huf: You have used brass for the key elements and a Zink alloy for the cylinder. Add water and the corrosion process gets a little help. A new mechanism is €300+ .

When the drivers door has been opened using the metal key and the +12V junction has been made available the use of a high current charger is a *must*. Otherwise when the charging voltage is applied, the alarm goes off. The instrument cluster starts to flash and a a lot of not very nice things happends. The current consumed is several amperes, and a low capacity charger cannot supply this power. E.g. the alarm needs a stable voltage source in order to be shut of. I guess that the instrument cluster high voltage circuitry is not to happy either.

 

[television]

Just looking at some answers here.

You cant use the cigar lighter though this is on the same feed as the radio and is Key1 only. it will though save the radio code if you have one.

Using a Auto charger is not good when the battery is dead flat as the voltage can be as high as 20 volts and many of our cars do not like that, a trickle charger is better where the voltage is more in keeping with the running voltage of the car (lowest setting)

some cars do have terminal post thats OK, where you do not, the large terminal on the stater motor is a direct feed to the battery, though hard to get to,no damage can be done.

I have heard of people joining into the fuse box, without know the inputs and outputs, dodgy to say the least.

Malcolm