Engine stops....Horn sounds?

[Simon]

No problems here

 

[zerocool]

how old is the car and what model is it?
could be a faulty rear sam depending on the year and model.
rear sam is the fuse box located in the boot,which also acts as a control unit.

 

[jimmy]

Originally posted by zerocool
how old is the car and what model is it?
could be a faulty rear sam depending on the year and model.
rear sam is the fuse box located in the boot,which also acts as a control unit.

I was hoping you would come up with some suggestions/answers.

It is a late 1997 C250TD Estate, Elegance, it is an import but according to the VIN no: it is buit to UK specification.

A few other things I have noticed:

1: Horn peeps sometimes when key is removed from ignition briskly. Coincides with ignition barrel motor thingy clunking as the key is removed. The key has to have been in position 1 or 2 for it to peep, will not do it if the key is left in position 0 for a second or two before being removed.

2: Rear washer pump getting a 1.5Volt supply when interior fan is on, stops when fan switched off?? Not enough current to make pump run properly and squirt water.

3: Heater/Ventilation control panel lights come on a second or two after all the other dash lights and are also slower to go off, is this normal?

4: Electrical interference being exagerated by spare wheel mounted amp and rear tailgate speakers, original door speakers running from headunit are unaffected.

5: The climate control fan near the rear view mirror sounds quite noisy when the ignition is first switched on before the main fan comes on.

I fitted a new heavier duty 88Ah battery yesterday, left it disconnected overnight and the car has been fine all day until this evening when it has started tooting at me again. The washer pump is still trying to run although I have disconnected it now to save the pump.

I have checked the battery voltage, about 12.54 volts stationary and upto 13.6 volts with engine running. The main battery to chassis earth has been cleaned as have the earths under the bonnet.

Zerocool, is there anyway I can check the rear sam myself or is it a replacement job? I am relying on you.

 

[GrahamC230K]

Originally posted by jimmy

3: Heater/Ventilation control panel lights come on a second or two after all the other dash lights and are also slower to go off, is this normal?

Normal to go off with a small delay, not noticed one coming on.

 

[Steve_Perry]

Originally posted by jimmy
3: Heater/Ventilation control panel lights come on a second or two after all the other dash lights and are also slower to go off, is this normal?

5: The climate control fan near the rear view mirror sounds quite noisy when the ignition is first switched on before the main fan comes on.

3. the delay is normal on later car's because the a/c control module gets the light signal from the ecu via CAN bus, it's not just a straight 12v feed to illuminate that section of the dash. So I've read

5. I'm sure other users of this board have suffered this problem but I can't remember the remedy to get a quiet fan Maybe a search might dig up the relevant posts?

S.

 

[zerocool]

all I can suggest is,get the fault codes read,as a new rear sam is about 200 quid.
sorry I can be of no more help.

 

[jimmy]

I have been having a job getting hold of the bloke I bought the car from, managed to speak to him today and he has agreed to pay to get an auto-electrician to look at the problems tomorrow.

I shall get a print-out of any fault codes from a friendly local garage and see what happens.

I spoke to the previous owner tonight and he knew of the horn problem as he spent £600 and then £400 at his MB stealer to try and sort the problem but they gave up unsuccessfully but still charged him.

He said the problem was very erratic and would sometimes go-away for months and months and then come back for a week or two. He said to do what he did and learn to live with it and remember to wait for a few seconds before removing the key. He was very helpful and said how pleased he was with the car and was reluctant to sell it, but a company car meant he had to sell it. (Or perhaps he got fed up with the horn beeping at him!)

It has'nt done it at all for the last 10 days or so. I doubt if the electrician will have any joy but he is said to be sh1t hot with alarm systems and an expert with MB electrics, so we will see.

 

[jimmy]

Originally posted by zerocool
how old is the car and what model is it?
could be a faulty rear sam depending on the year and model.
rear sam is the fuse box located in the boot,which also acts as a control unit.

I think your'e right zerocool:bannana:

Myself and the auto-electrician traced the fault back to the fuse/relay board under the bonnet on the drivers side. Underneath the relay board is a control unit with the part number:

022 545 53 32 [SAM]

I am guessing the [SAM] bit means it is the SAM unit that you suggested, except mine is up-front. This unit controls most accessories, horn (fanfare ), wipers, ventilation etc. This explains the horn fault and the washer pumps running with the ventilation fan, oh we discovered that both front and rear washer pumps were getting a voltage feed that varies with the speed of the interior fan.

When I phoned the local stealer and asked for a price for the above part number he said straight away; " Ah yes a SAM unit, we sell alot of them, common fault on the 202's"

Anyway, I was quoted £120 less 10% plus the vodka and tonic, can any of you negotiate a better price do you think?

Zerocool, do you know if this control unit is plug and play or does it have to be re-programmed/coded to the car?

The electrician managed to re-wire the horn relay so that it is now fed by an ignition switched positive so that it can no longer beep at embarassing times.

 

[GrahamC230K]

Sounds like the part that meant I could only indicate right when the car felt like it on my C200.

Controls lots and a common fault. Mine was done under warranty, but I think it was about that price.

If it is the oblong multi pinned relay type looking box thing I am thinking of, it's just plug and play.