Only left side indicators flash on lock-unlock.

[TudorKing]

Hi,

I purchased a 1997 C180 Classic yesterday and have noticed that only the indicators on the left hand side flash when locking or unlocking.

Does anyone have any ideas as to where I should start looking please.

 

[Ted]

Just a guess - try turning the hazards on and off a few times and see what happens.

 

[TudorKing]

Hi Ted,

Thank you for your reply.

I tried the hazards as you suggested, but unfortunately it had no effect.

The indicators on both sides work when I put the hazards on.

 

[Dec]

Test your alarm, if its not working properly then unplug the alarm siren.
See here… http://www.mbclub.co.uk/forums/electronics/169666-w202-how-test-car-alarm.html

Dec

 

[TudorKing]

Hi Dec,

Thank you for your reply.

I tested the alam as you suggested and the siren went off very loudly.

 

[Dec]

When you tested, did all 4 hazards flash as well s the siren sounding?

I think fuse number 7 - 5amp - in the boot, is for the alarm, remove it to see if it makes any difference to your problem.

If your alarm siren is the original factory fitted unit then its about 16 years old now, these alarms usually give trouble at this age, however we don’t know for sure how old your alarm is, it could be faultless and may have been replace recently.

Dec

 

[TudorKing]

Hi Dec,

Thank you so much for taking the time to help me.

I took a look at the fuses in the boot and there was not a fuse in the slot labeled for the Anti-Theft Alarm.

I have now noticed a sticker on the rear passenger window, photo attached.

 

[Dec]

I’m not so sure about my own fuse box in above picture, I just noticed that according to the list of fuse ratings (bottom of my picture) fuse 2 – 4 are 5amp and fuse 7 is 7.5 amp so my fusees are wrong, must check that out tomorrow.

Edit, ignore the above as it’s incorrect. The fuse layout as depicted in my picture is correct after all.



You should have the same fuse chart as mine inside your fuse box lid.
My alarm window sticker is slightly different to yours, mine is a UK car, is your car UK too?
When you tested, did all 4 hazards flash as well as the siren sounding?

Don’t pull any more fuses out of that fuse box until you can check that you can open the boot lock with the metal key blade because fuse 2 and 4 are listed for the central locking… if you removed the fuses for the centeral locking vacuum pump then the boot wont open with the remote fob or cabin switches.

Dec

 

[Ted]

Does the 202 have a pse pump?
Pretty sure that was what activated the indicators on locking on my 170.
Wires will be black/white and black/green.

 

[Dec]

It has a PSE pump alright, I think that all that the PSE pump does is to inform the alarm siren that he car is being locked, so as it can arm itself.

My understanding is, for example, that if the alarm siren were to be disconnected /unplugged then the hazards won’t flash when locking and unlocking, also, if a door or the boot or bonnet is intentionally left open and the car is then locked, with the remote, then the hazards will flash 2 times instead of the usual 3 times.

The purpose of the hazards flashing is to visually indicate arming and disarming of the alarm, that’s what makes me think the OPs one sided flashing problem in some way involves the alarm siren.

Dec

 

[TudorKing]

Hi Dec,

Only the left hand hazards flashed when the a siren sounded.

There are only 4 fuses in the fuse box in the boot, photo attached.

 

[TudorKing]

Do you think that the alarm is an after market one? I have attached a photo of a funny key thing that came with the car that the trader I purchased the car from said he didn't know what it's for.

 

[Merc Owner 2B]

That looks like an aftermarket immobiliser contact fob. Is there anywhere on the dash to plug it in? May not even be for your car since it's obviously starting without it.

 

[TudorKing]

Hi Merc Owner 2B,

I have had a jolly good look and can't find anywhere for it to plug in.

 

[Dec]

If you don’t have the switch pictured below on your dash then you have an aftermarket alarm, probably a Scorpion Alarm so most thing in this thread doesn’t apply to you. Similar type of alarm “dongle” here Bert Rowe's-A-class info. Information A160/Feb 2002 Scorpion Car Alarm System.

Your boot fuse box is also of a 1996 car and therefore different set up to my 1997 car, your car was probably made in late 1996 and first registered in early 1997.

What type of key fob/s do you have?

Dec


Edit; it appears that the “dongle” in your picture is for the purpose of deactivating the alarm and immobiliser so its use is to by pass the security in the event of a fault.

There is probably a place to plug it into somewhere close at hand to the drivers seat… glove box perhaps?

 

[TudorKing]

Hi Dec,

Thanks for replying again.

My car does not have that switch on the dash.

It was first registered in February 1997.

I have searched and searched for a place to plug the dongle into, but just can't find one.

A photo of my key is attached, it came with two identical keys.

 

[Dec]

As you have possession of a dongle then there must be a place somewhere to plug it in, it should be located somewhere convenient for the driver to reach, maybe under steering wheel, above drivers knees.

Your key type confirms that your alarm is different to the later 1997 W202 like mine, you have an alarm system similar to the one in my previous link… Bert Rowe's-A-class info. Information A160/Feb 2002 Scorpion Car Alarm System.

The failure to flash on one side may be due to a lose OR bad connection on a wire at the alarms control box, maybe just wiggling the wiring that plugs into the alarm control box might cure the fault.
The alarms control box is likely to be located under the passenger side foot rest OR below the instrument cluster behind the panel just above the driver’s knees, no idea for sure where it would be located.

Dec

 

[TudorKing]

Hi Dec,

That sorted it just lovely

Thanks for all your help on this, you are a total dude!