C200 W203 All rear lights flashing!

[ik_uk]

Greetings All,

I have an odd problem - all my rear lights flash when they turn on. The boot light constantly flashes. The tail lights flash when they come on as well as the number plate lights. When reversing the reverse lights flash.
I took it along to a 'specialist' and he first thought it was the fuse box so got that changed but fixed nothing. Now he thinks it's the looms.
Another mechanic reckons it's not that and thinks it's the front headlamp units which needs replacing. He tried tying some wires to bypass something or other in the headlamps and all looked good until I drove a hundred yards.

Some other info which may be relevant:

• the heat shield fell of the exhaust a few months ago and the boot floor now gets very warm
• there's a ticking sound from inside the boot in rhythm with the flashing (left hand side in the boot)
• the petrol indicator light shows emptry when tank is full but seems to get better as petrol level decreases

Any thoughts before I hand over money to the main dealer?

tia,
ik

 

[paf]

do you have a tow bar?,is this happing when the indecators are on or off or both?,without testing its hard to say,but my first test would be a bad earth.try running a wire from the battery - (neg) to the outer metal caseing of the rear light thats flashing,just hold it on there while its flashing if it stops flashing then thats the problum,good luck,try not to touch any other conections or your be replacing fuses!!.

 

[type49]

Sounds like a problem with rear SAM. Bit of a long shot but worth disconnecting the battery for a couple of minutes & then try.

 

[Cole@MBS]

But then you run the risk of frying the rear sam by doing that, you cant win with a 203!!!

 

[ik_uk]

Thanks for the replies.

No towbar. Not sure how to try earthing since all the rear lights flash and not one particular one. I tried disconnecting the battery but that didn't fix the problem.

I took a look at the rear fuse box and started disconnecting the wires going in. Disconnecting one of them did stop the boot light flashing and it remained on as it should but all the other rear lights didn't come on.
I also removed one of the ticking relays and though the ticking stopped the boot light was still flashing.

Not sure what a SAM is - the only one I know of takes out planes....!!

Could it be that I need to replace the the fuse box? It had gone a little green on the circuit board. Corrosion perhaps?

 

[television]

The rear SAM should not have any corrosion on it, they are sensitive ECU's that contain stored info as to what the car has.

Your alarm, locking and lights / indicators run through this ECU any sign of corrosion and the circuits inter react giving non sensible faults

The picture shows on of my SL SAMs, that was very bad, what you could try is to wash it off with say lighter fluid and a toothbrush to remove all of the green algae make sure that it dry and try it again

 

[paf]

if you have green on your rear sam it means the copper conections/tracks are caroding(we cant all spell!),"telivision" is right you need to try and clean the caroded tracks/conections i would be more inclined to use viniger!(dont laugh)the copper has oxidized and the acid needs to be removed,check for any track brakedges after and solder them,failing that it looks like a new/secondhand SAM (ouch).

 

[type49]

Thanks for the replies.



I took a look at the rear fuse box and started disconnecting the wires going in.
Not sure what a SAM is - the only one I know of takes out planes....!!

Could it be that I need to replace the the fuse box? It had gone a little green on the circuit board. Corrosion perhaps?

The rear SAM (signal acusition module) is part of the rear fuse box, so sounds like you've found your fault

 

[television]

if you have green on your rear sam it means the copper conections/tracks are corroding(we cant all spell!),"television" is right you need to try and clean the corroded tracks/connections i would be more inclined to use vinegar!(don't laugh)the copper has oxidized and the acid needs to be removed,check for any track breakages after and solder them,failing that it looks like a new/secondhand SAM (ouch).

I think that the copper tracks are too thin to use acetic acid (vinegar) if you do no more the 2% proof. If it does the trick then take it out and spray it with clear lacquer

 

[ik_uk]

I've removed the rear SAM and it looks like this:

I can't take it out completely to see the other side - should I force it? It seems to be stuck down.

If the cleaning doesn't do the trick is it worth getting one from a refurb place?

 

[paf]

bite the bullit

you can see corosion on the lower joints id clean them up (any good with a small soldering irion? it might pay you to rejoint the 2 worst i can see)if that still doesent do the trick then you need to look at the other side of the board! if its coroded on one side then chance's are its the same the other side!,if cleaning one side doesent work then you havent got anything to loose as your have to get another so you might as give it a try at the other side?!!.
and if it does work dont forget to lacuare it to pervent it again!! (hair spray is good!)

 

[ik_uk]

I tried t cleaning with vineger and a toothbrush and got rid of the green stuff but there probelm is still there.
I tried to dismantle the thing to get to the other side but it seems to have layers of plastic that I can't take off. Have tried removing all the relays and opening all the clips but no luck.

I've resigned myself to getting a replacement. Is it just a matter of getting a new fuse box from the scrap yard? What are the chances that I get a dud or worse the problem lies elsewhere ? A new one worth considering....?

 

[paul vp uk]

worried now electrics 04 vito

I only hope I have done the right thing buying my 04 plate vito ,
over the years my landrover 300 tdi's have allways been easy to fix not expensive on parts, However he more i read the more i am thinking i may have made a mistake , so many problems and I expect merc parts are realy expensive!!
surley with so many on the road all the vito even if the are made oin spain cant be that bad, or am i being nieve

 

[Blobcat]

I only hope I have done the right thing buying my 04 plate vito ,
over the years my landrover 300 tdi's have allways been easy to fix not expensive on parts, However he more i read the more i am thinking i may have made a mistake , so many problems and I expect merc parts are realy expensive!!
surley with so many on the road all the vito even if the are made oin spain cant be that bad, or am i being nieve

Very few members come here to say how good their cars/vans are, they generally arrive because they are having a problem. I wouldn't worry too much you could have a TD5 and go wading, now that would give you some electrical issues...

 

[ik_uk]

Update: It was the rear SAM. Had it replaced with a new one and £350 later all is now fine!
Thanks for your help.