relays

[cobalt]

Hi
1997 s280 w140
Can anyone pleasr tell me the location of the COMBINATION RELAY my indicators/rear screen heater/wipers have just stopped working and this seems to be a likely cause also is there any way of testing the relay before buying a new one £195 from the dealers +£80 fitting.

 

[tom7035]

Should be in the driver's side corner of engine compartment, behind the fusebox. Unclip the fusebox cover then remove the retaining screws for the housing lid. You should hear the relay clicking when it energises.
Checked your fuses are all clean and firmly installed?

 

[television]

Its known as the N10 and it should be the biggest one in the box, Do what TOM says and check all fuses, if everything has stoped it could be worth opening up the box to see what is wrong.

Malcolm

 

[cobalt]

Thank you for the info I found it where you said it was can you tell me if the relay has gone would I have power at the fuse with the fuse removed I have power to one side of the fuse.

 

[tom7035]

I'm not a 'sparky' and television is the guy to answer, but I think you'd have to have power to one side from the battery then the current would be transmitted via the fuse (when inserted obviously) to the relay concerned. Malcolm will come in with the technical details......................

 

[Blobcat]

I'm not a 'sparky' and television is the guy to answer, but I think you'd have to have power to one side from the battery then the current would be transmitted via the fuse (when inserted obviously) to the relay concerned. Malcolm will come in with the technical details......................

I think a 'Lecky' is what is required rather than a 'Sparky'

if the relay has gone would I have power at the fuse with the fuse removed I have power to one side of the fuse

It depends if the relay is before the fuse in the circuit. With the fuse out do you have power to the relay? if not then the fuse is before the relay and appears to be working ok (assuming the fuse hasn't blown that is)

 

[television]

The answer here is not straight forward, Many relays are multy function items, and many devices have more than one power supply, ie a wiper motor can be powered by a 12v supply with its own fuse. The control of the wiper motor is done within the relay box that can also be fused. the input on all MB's to the control relay's is always number 30, where relay have an output, its always pins 87 (pins as often more than one) but this is not the case for the N10 multi function box. Without a voltmeter to know whats going on make it very hard as you are working in the dark.
Re the fuses in genral, certain cars have had problems with the fuse holders.
the +12volt is normally fed from one side of the fuse by a common bus bar, putting a test meter into the hole on the top of the fuse will indicate that you have 12volt on that fuse,but in the case of a poor fuse holder , that does not mean that you have 12volt going out on the other side. Often a fuse will burn a little and lose contact, taking them out and cleaning lightly with switch cleaner does help, also turning the around so that any arc burns are not in the same place.

I have a spare relay that came with my 129 (same) I will open it later in the week, and see what is in there, I do not know if it is faulty or not.

Malcolm

 

[cobalt]

relay

Tanks for the replys guys I ordered a relay today from e/u parts £60 a bit different than the stealers I"m sure you will agree still not sure if the relay is duff but for £60 I"ll give it a try I will keep you posted on this one.
Thanks again
COBALT

 

[ken bishop]

Did the new relay solve the problem?
Ken BIshop

 

[Ben Longden]

Malcolm,
In the W140 is the relay box behind the fuse box (between the fuse box and cabin) or elsewhere, as there appears to be a big rectangluar style plug at this location....

(Im looking for the headlight flasher relay).

Ben

 

[television]

I do not think there is a relay

http://www.autolib.diakom.ru/CAR/Mercedes-Benz/1994/S500/SYSTEM WIRING DIAGRAMS/5252.pdf

 

[Ben Longden]

Thanks!!!!

So, it would appear the switch is all done in the sterring wheel stalk... and then via fuse 14.
Once it cools down outside (its 42) I will check it.

By the way, its nearly 5am UTC... what are you doing up at this godless hour?

 

[television]

Thanks!!!!

So, it would appear the switch is all done in the sterring wheel stalk... and then via fuse 14.
Once it cools down outside (its 42) I will check it.

By the way, its nearly 5am UTC... what are you doing up at this godless hour?

Lilian my wife is very ill again, the doctors service is zero we get the doctor every other week, its crazy.

By the way you will need some heat sink paste to mount the new reg pack on your heater fan.