w220 350 electrical problem

[bonchester]

Car blew 2 40 amp fuses,the ones under the passenger seat. I replaced them and now i have multiple problems - no electric seat adjustment, no horn, no command,no ac, no windows,mirrors,drivers side front lights. Any ideas please after having checked all fuses many times. In other words help!

 

[Craiglxviii]

Sounds like a a SAM problem to me.

 

[bonchester]

well i have changed the right hand sam but it has made matters worse. It was put on a mercedes diagnostic system which stated it was the right sam. Any ideas please?

 

[mioba]

It might be the right sam bu part number but it needs marrying to the car. Ie programming

 

[bonchester]

It might be the right sam bu part number but it needs marrying to the car. Ie programming

thanks for that. How is that done?

 

[mattkh]

thanks for that. How is that done?

What year is the car..?

 

[bonchester]

What year is the car..?

2003,april.

 

[mioba]

thanks for that. How is that done?

You will need an indy with STAR or a MB dealer.

What was the "MB dignostic system" you refer to?

 

[Botus]

the electrics on a w220 are built as long term entertainment projects, there are LOTS of posts about 6 months chasing faults and 5k bill from main dealers before it will start (where they were doing you a favour, having spendt 9k in labour and on replacement ECU modules)

(don't forget all S classe's are techno development mules for all the other models that follow over the next 5 years) by the time you got to this era, I doubt the SAM is plug and play. It will probably need specific software customisation (aka coding) for the toy count in your actual vehicle using dealer tools

But equally as likely as a low volt battery and a few aging modules will be corrosion on multiple can bus connectors around the whole vehicle. I'd start by getting the carpet up on the left front and remaking any multiplug connector you can find and using something like ACF50 to knock back the corrosion. Can bus works on very subtle signals at really low volts to tell half the car how the world works... it became about a million times less problematic on later mercs

You need dealer diagnostic kit, a massive power supply keeping it at 14 v whenever you try to find out whats going on and to keep chasing your tail getting every module to to get over its temporary migraine...

see you in a week when you remade some connections and finally worked out an 11 v battery is holding you back

 

[mioba]

btw. best resource for the w220 is here if you are hands on

W220 S-Class Encyclopedia

w220.wiki

 

[bonchester]

You will need an indy with STAR or a MB dealer.

What was the "MB dignostic system" you refer to?

it was a star system. to explain the story --- i was in a rush,my wife needed the car and it wouldnt start so in the dark and in a rush i attached the jump leads in correctly. of course it was very stupid of me. hence the 2 40 amp fuses blown and since then all the problems. i thought that the sam was plug and play! the car starts,drives but the seats,command,ac etc dont work.

 

[bonchester]

the electrics on a w220 are built as long term entertainment projects, there are LOTS of posts about 6 months chasing faults and 5k bill from main dealers before it will start (where they were doing you a favour, having spendt 9k in labour and on replacement ECU modules)

(don't forget all S classe's are techno development mules for all the other models that follow over the next 5 years) by the time you got to this era, I doubt the SAM is plug and play. It will probably need specific software customisation (aka coding) for the toy count in your actual vehicle using dealer tools

But equally as likely as a low volt battery and a few aging modules will be corrosion on multiple can bus connectors around the whole vehicle. I'd start by getting the carpet up on the left front and remaking any multiplug connector you can find and using something like ACF50 to knock back the corrosion. Can bus works on very subtle signals at really low volts to tell half the car how the world works... it became about a million times less problematic on later mercs

You need dealer diagnostic kit, a massive power supply keeping it at 14 v whenever you try to find out whats going on and to keep chasing your tail getting every module to to get over its temporary migraine...

see you in a week when you remade some connections and finally worked out an 11 v battery is holding you back

gulp!

 

[mioba]

ahhh Has the car got an OVP relay. If so disconnect for a few mins then put it back.

 

[bonchester]

ahhh Has the car got an OVP relay. If so disconnect for a few mins then put it back.

i dont know to be honest. if it had where might it be?

 

[Botus]

oh dear connecting these up back to front is rather problematic,

puddles under the carpets is usually what sets the can bus off on a merry go round, if you zapped it back to front, you will need support on this and a few critical modules to test mix and match with...

 

[bonchester]

oh dear connecting these up back to front is rather problematic,

puddles under the carpets is usually what sets the can bus off on a merry go round, if you zapped it back to front, you will need support on this and a few critical modules to test mix and match with...

there is no water ingress but i certainly did mess up with the jump leads. i could kick myself as i have never done this before. i am ok with spanners etc but electrics are beyond me. which critical modules? sorry to appear as useless but in this instance i am,just need any help.

 

[Botus]

I've been trying to put a positive spin on it, but really these were super fragile at the best of times. connecting back to front could have popped lots of critical modules. But working it out is going to be complicated. The can bus corrosion and low volts issues means usually all modules come up as dead one min and OK the next.

can you get it to run now or ? If it runs you have a chance with some ebay second hand bits and a patient expert coaxing it back to life

 

[bonchester]

Yes it runs and goes just no seat adjustment no drivers windows, no mirrors,no command ,no ac,no drivers side lights,no radio/cd

 

[Paul Garrett]

Oh boy so glad i never used jump leads when the old battery gave out! So i can only imagine the annoyance you feel of doing so, esp connecting wrong way round!, just hope you get things sorted and as cost effecient as poss?, i bought a power pack to boost battery if ever needed, also a trickle charger to keep new batt in good health when not using car for long periods, low battery causes all kinds of mayhem within the system esp on a S500! so could be an idea to go this route when sorted?, best of luck

 

[mioba]

No problem with using jump leads if you do it right.
made the same mistake on my w124 moons ago and it was the OVP, but the problems were everywhere.
The W220 was however the start to electronic everything in mercs.

doesnt help the op but is as