No electrics - CL 500 54 model

[Parkheadlad]

No response from my CL 500 (2004) when I used my fob to unlock the doors. Battery is fully charged. For the last 6 months I have had a parasitic draw (0.28A) from the battery so any time I parked up I removed the negative lead from the negative battery terminal. Never had a problem starting the car when reconnected. Recently I parked up for 9/10 days and as stated above a ' dead' car when I reconnected the negative lead. Reluctant at the moment to open the driver's door manually with the key as the door and windows are soft closing - closing the door will not be 'true' as the driver's window will nor reset due to lack of any power. This happened once before - I simply disconnected and reconnected the negative lead which solved the problem.
Any thoughts very welcome.

 

[SL63 Mark]

If it's any help, to re-set the windows in the R230 you just drop the windows, close the door, get inside, shut the door, raise the windows, keep the window buttons in the fully raised position for approx 10 seconds and the windows will re-set. I assume the CL is the same, worth trying.

 

[Parkheadlad]

After 3 weeks of my Merc sitting stationary, it's time I think to call in the experts. Still a mystery why there is no power to any part of the car. As I said above the battery is fully charged but just to double check I tried a jump start with my other car with a heavy duty battery but no joy. When I reconnected the negative lead, the boot illumination bulb very briefly flickers then nothing.Any last suggestions before I phone a garage tomorrow would be greatly received.

 

[Craiglxviii]

Sounds like you have a relay sticking open. 0.28A drag is high, but not enough to cause the battery to die overnight (7A-h/ day).

 

[Craiglxviii]

Common parasitic drag reasons on the 215… alternator diode pack failure, starter motor grounding failure, COMAND head unit failure.

 

[Parkheadlad]

Thanks Criaglxviii. Checked again today and the parasitic draw was up to 1.85A...then it would drop momentarily to 0.7A then back up to 1.85A. Very frustrating!
With ref to the sticking open relay, are you saying this may be causing the parasitic draw or the reason why there is no electric power to any parts of the car?
Regards

 

[Craiglxviii]

Thanks Criaglxviii. Checked again today and the parasitic draw was up to 1.85A...then it would drop momentarily to 0.7A then back up to 1.85A. Very frustrating!
With ref to the sticking open relay, are you saying this may be causing the parasitic draw or the reason why there is no electric power to any parts of the car?
Regards

Potentially both, dependent on what the relay led to. For a draw that big though I would look at the alternator voltage regulator/ diode pack or starter motor in the first instance.

 

[Parkheadlad]

Thanks again.

 

[Parkheadlad]

I checked all fuses in the car (4 fuse boxes) and I tracked the draw to 2 fuses: Right front door module - fuse No 39 ( drawing 0.1A) and fuse number 78 (end of dashboard) which was drawing 0.06A -
Alarm signal horn with additional battery
Steering column module
EIS control unit
ME-SFI control unit.
No clue how to tackle these issues.

 

[Craiglxviii]

I checked all fuses in the car (4 fuse boxes) and I tracked the draw to 2 fuses: Right front door module - fuse No 39 ( drawing 0.1A) and fuse number 78 (end of dashboard) which was drawing 0.06A -
Alarm signal horn with additional battery
Steering column module
EIS control unit
ME-SFI control unit.
No clue how to tackle these issues.

Sure, but that’s 0.16A, you’re still missing 95% of the drag!

 

[Parkheadlad]

Forgot to mention that up until very recently the draw was 0.2A and that was when I did my ' detective' work and located the majority of the draw. But that was then.......

 

[alexanderfoti]

Sure, but that’s 0.16A, you’re still missing 95% of the drag!

EIS + Alarm siren will easily draw that when awake.

 

[Parkheadlad]

I am literally at my Merc now and I am going to test every fuse (4 fuse boxes) and every relay and check any fusable wire I can see.

 

[Craiglxviii]

EIS + Alarm siren will easily draw that when awake.

Oh good spot, yes true. I never had that issue with mine. I had literally every other issue but not that exact one.

 

[Parkheadlad]

Managed to get the car going. Nothing to do with the electrics - long story but just me being a wee bit thick. Tested all the fuses - believe it or not but I have 8 fuses drawing power ranging from 0.01 - 0.19 (0.01 0.07 0.12 0.07 0.04 0.15 0.19 0.07) - total of 0.72A. The reading at the battery is a draw of 1.88A!! It very briefly drops to 0.71A then back up to 1.88A. Bit of a nightmare. Interestingly I have contacted three different auto technicians and they are not interested - they say it's far too much hassle to solve these electrical problems in older Mercs.
So I do appreciate the advice I'm getting from you guys. So parked up the car, disconnected the negative terminal lead and will check the relays tomorrow.

 

[alexanderfoti]

We can sort it, but you'd have to get the car to us

 

[Parkheadlad]

I live in rural West Cumbria so probably miles from anyone......but willing to take up your kind offer and travel to sort this annoying issue.

 

[alexanderfoti]

I live in rural West Cumbria so probably miles from anyone......but willing to take up your kind offer and travel to sort this annoying issue.

We have a recovery chap that goes up and down and is fair.

I don't mean to imply that I know the fault and won't tell you. We would still need to carry out diag

 

[Parkheadlad]

Sounds like a plan! Could you give me an idea of when you will be available and a very rough idea of cost. Cheers

 

[alexanderfoti]

Sounds like a plan! Could you give me an idea of when you will be available and a very rough idea of cost. Cheers

Give me a call on the workshop tomorrow at your convenience, and we can sort something out - 0203 384 4644