SL500 flattening battery explanation - sound likely?
Discussion
Hello all,
I've had another development in my infuriating buzzing fans/clicking relay/draining consumer battery saga.
It went in to Merc in Leeds yesterday with instructions to basically "fix it".
I got it back and it wasn't fixed, but they say they know what's wrong.
They reckon it the heater control unit - it's the knobs and assembly beneath the COMAND. This has it's little fan buzzing away continuously (as well as the battery cutoff relay in the boot clicking away and the COMAND fan running continuously). Price including fitting £862.45.
The thing is this: if I pull the heater control unit fuse this does indeed stop the buzzing fan. However the COMAND is still doing it's stuff and the relay in the boot is still clicking. To me this would seem, on the face of it, to say that it's got nothing to do with the heater control unit, and that it's a symptom, not a cause.
Or am I looking at this too simplistically, and just pulling the fuse isn't actually doing anything to stop it causing the rest of the stuff?
It all seems a bit doubtful to me, although I'm not a trained Merc tech, of course. If it's fixed by replacing this unit then I'll be very happy indeed and consider it a relative bargain (I cannot tell you how much it is doing my head in - it's ruining my pleasure in an utterly fabulous car) - however I'd not be very impressed if I chuck 800 quid at it and it doesn't solve my problem.
I've had another development in my infuriating buzzing fans/clicking relay/draining consumer battery saga.
It went in to Merc in Leeds yesterday with instructions to basically "fix it".
I got it back and it wasn't fixed, but they say they know what's wrong.
They reckon it the heater control unit - it's the knobs and assembly beneath the COMAND. This has it's little fan buzzing away continuously (as well as the battery cutoff relay in the boot clicking away and the COMAND fan running continuously). Price including fitting £862.45.
The thing is this: if I pull the heater control unit fuse this does indeed stop the buzzing fan. However the COMAND is still doing it's stuff and the relay in the boot is still clicking. To me this would seem, on the face of it, to say that it's got nothing to do with the heater control unit, and that it's a symptom, not a cause.
Or am I looking at this too simplistically, and just pulling the fuse isn't actually doing anything to stop it causing the rest of the stuff?
It all seems a bit doubtful to me, although I'm not a trained Merc tech, of course. If it's fixed by replacing this unit then I'll be very happy indeed and consider it a relative bargain (I cannot tell you how much it is doing my head in - it's ruining my pleasure in an utterly fabulous car) - however I'd not be very impressed if I chuck 800 quid at it and it doesn't solve my problem.
52K '02 plate.
I realise it's expensive, however I knew that when I bought the car - and to be honest what modern car of any make is any different? Any of the little black boxes gives up the ghost and you're looking at big bills.
I'm not going to lose sleep if it fixes the problem. As long as it doesn't turn into one of those oft heard sagas of being in the shop once a week while random parts are replaced. That *would* bother me.
I'm just going to book it in next week; if it doesn't cure the problem then I'll be negotiating on the bill.
I realise it's expensive, however I knew that when I bought the car - and to be honest what modern car of any make is any different? Any of the little black boxes gives up the ghost and you're looking at big bills.
I'm not going to lose sleep if it fixes the problem. As long as it doesn't turn into one of those oft heard sagas of being in the shop once a week while random parts are replaced. That *would* bother me.
I'm just going to book it in next week; if it doesn't cure the problem then I'll be negotiating on the bill.
Orb the Impaler said:
52K '02 plate.
I realise it's expensive, however I knew that when I bought the car - and to be honest what modern car of any make is any different? Any of the little black boxes gives up the ghost and you're looking at big bills.
I'm not going to lose sleep if it fixes the problem. As long as it doesn't turn into one of those oft heard sagas of being in the shop once a week while random parts are replaced. That *would* bother me.
I'm just going to book it in next week; if it doesn't cure the problem then I'll be negotiating on the bill.
From my experiance some makes have more black boxes than is absolutely necessary and are more prone to giving up the ghost than others.I realise it's expensive, however I knew that when I bought the car - and to be honest what modern car of any make is any different? Any of the little black boxes gives up the ghost and you're looking at big bills.
I'm not going to lose sleep if it fixes the problem. As long as it doesn't turn into one of those oft heard sagas of being in the shop once a week while random parts are replaced. That *would* bother me.
I'm just going to book it in next week; if it doesn't cure the problem then I'll be negotiating on the bill.
God strewth!
I decided to pop into MB today and have a chat with the tech that had run the diagnostics on my car; understandably I wanted to make sure that spending 852 quid would solve the problem
I asked him about how the heater control unit could be making the relay in the back keep clicking. "What relay?". Oh dear. As I suspected the heater control unit fan running is a symptom of the relay problem, not the cause. It's a pisser cos all this stuff was written out in bullet point form for them; why wasn't it passed on? And why didn't they spot this? Do they simply plug a machine in and not use the senses they were born with?
Back in again on Friday for more diagnostics (at their expense this time). This is going to be like pulling teeth....
I decided to pop into MB today and have a chat with the tech that had run the diagnostics on my car; understandably I wanted to make sure that spending 852 quid would solve the problem
I asked him about how the heater control unit could be making the relay in the back keep clicking. "What relay?". Oh dear. As I suspected the heater control unit fan running is a symptom of the relay problem, not the cause. It's a pisser cos all this stuff was written out in bullet point form for them; why wasn't it passed on? And why didn't they spot this? Do they simply plug a machine in and not use the senses they were born with?
Back in again on Friday for more diagnostics (at their expense this time). This is going to be like pulling teeth....
bolide said:
Orb the Impaler said:
Do they simply plug a machine in and not use the senses they were born with?
I think you know the answer to that one...I have managed to trace poor performance to the wrong headlamps being fitted and the Rear wash wipe not working doe to 1 missed bit of coding when the ign switch was replaced and other weird faults.
BUT!
Tech training aint what it once was.
I have know Techs " diagnose by mental telepathy" guess at a part that is not in stock and hope that when the part arrives they don't get the job.
I have known cases of dealers who call the manufacturer for assistance without even looking at the fault.
I have arrived and diagnosed/fixed cars that have been in to numerous dealership for a fault withing 10 mins of arriving.
Sadly there is NO legal requirement for any qualificationto be allowed to work on your P & J.
As a rule of thumb the Darwin principle applies.
Good staff end up in big dealerships with a Brand because thats where the money is.
The Pond life ends up in indy under the arches.
That is not black and white, obviously as I know a very few good indy and quite a few crap big dealers too.
Last year I had a truly shocking experience with an independent Merc place - I'm talking stuff like charging for suspension parts when really all they did was tape up the roll bar to take the play out of the ARB bushes, charging for not replaced filters, 20W50 oil etc etc.
Anyone who wants to know who can PM me. I actually posted details and it got modded due to the name and shame posting rules. Hopefully personal comms are permitted.
Anyone who wants to know who can PM me. I actually posted details and it got modded due to the name and shame posting rules. Hopefully personal comms are permitted.
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