Electrical problems

[gsmcd]

This is my first MB - a 2001 C320. Nice car. My problems started yesterday when I did a good deed helping a lorry driver to reverse. Locked the car as normal came back to it and the hazards were going very fast indicating the alarm had activated. No noise. Put the key in and everything seemed to work...........until:

Central locking works intermittently - usually have to enter car using the physical key - which is a real pain.
Radio hisses but stations are inaudible (CD works OK).
Headlights remain on whilst engine is running irrespective of where the switch is.
Boot release on the key fob doesn't work at all.

The LED on the key fob does illuminate when pressed.

I'm tempted to disconnect the battery and see what happens (will have to find the radio code again).

Any advice greatly received!

 

[television]

Hello and welcome, the antenna amp in the rear is a common fault, this would upset the radio and long range locking. Some of this points to the front SAM going down

 

[gsmcd]

Sounds expensive! I have a local independent that specialises in MB and BMW - time for a visit.
Is there any point in disconnecting / reconnecting the battery?

 

[television]

By all means try it, but 203,s are funny cars in this respect please see here
http://forums.mercedesclub.org.uk/showthread.php?t=37364



I cant tie the 2 faults together, the SAM controller is up front, with lights, indicators, and the locking and antenna in the rear, the SAM's are interconnected.

The fault codes will be recorded, and it will take someone good with electrics to understand what is going on.

Has just one or 2 fuses blown, the locking is electric on the 203

I cold take a look at all of the circuits and try and find a common link, please ask if your indie is unsure as it is expensive just to try parts. He will need the MB STAR kit to see what has gone on

 

[gsmcd]

Thanks Malcolm - I will look at fuses tomorrow and post if I find anything.

 

[gsmcd]

Fuse No.8 blown. Blows immediately I try to replace it. disconnected battery and replaced it - blows immediately on reconnection. I now get a message about the Electronic Stability Programme not being available!
Trying to get it in to local MB dealer as independent can't see me 'till Tuesday and I'm away all week.

 

[television]

Turning the steering from lock to lock will remove the ESP light and normal with a battery disconnect.

I am checking on that fuse to see what it does

 

[television]

Fuse number 8 fits exactly with what I said, its the antenna amp use for the amp in C panel, it also drives the alarm horn.

The chances are that the horn has gone short circuit, and you could just unplug this and drive the car OK without this alarm horn in, and just replace the fuse 8, then the radio will work and you should be back to normal.

The antenna amp will be OK

We have had 5 of these horns going short circuit this week, please post with what MB want to do

 

[gsmcd]

That makes sense as the alarm horn didn't work when the hazards were flashing at double speed. Is the horn easy to disconnect?
I will report back on what the main dealer says.

 

[television]

That makes sense as the alarm horn didn't work when the hazards were flashing at double speed. Is the horn easy to disconnect?
I will report back on what the main dealer says.

Dead easy on a 203 and 10 in the kink

http://www.detali.ru/cat/oem_mb2.as...GM=716.667&CT=F&cat=69J&SID=82&SGR=525&SGN=23

Just unplug it

 

[gsmcd]

Can't even see it? Took the moldings off the engine and in the position shown in the diagram is part of the air filter!?

 

[television]

I have sent you an Email with the instructions

 

[gsmcd]

Naa. Can't even see the thing. Took all the engine moldings off and in the position shown in the diagram is part of the air filter system!??

 

[gsmcd]

Got your email Malcolm - thanks. I'll crawl under there and disconnect tomorrow.

 

[television]

Reading that document it says its under the wheel arch liner

 

[television]

Another paper sent for this

 

[gsmcd]

Main Dealer report: I didn't get a chance to look at the siren as we had visitors. So took the easy route and booked it into the local main dealer. I paid for the convenience!
After running a 'short test' (£23.64) they conducted an electrical system check (£55.16) and identified the siren as the problem - which is what I told them when I walked through
the door. £75.00 for the actual siren plus £31.52 for labour and £1.00 for two fuses.
The total bill including the contribution to some bankers pension fund (aka VAT) was £214.27. A lot of money for what it was but I had to get it done before Monday.
Malcolm was spot on with his analysis. Many thanks to him. If it ever happens again I will have the siren removed and the alarm wired in to the horn as posted on this site.

 

[gsmcd]

By the way of an update, total bill was £230. The part (the anti-theft siren was £75.00).

 

[television]

By the way of an update, total bill was £230. The part (the anti-theft siren was £75.00).

Not too bad then, you did tell them what the fault was