N10 Combo Relay Carnage on my R129!!

[davidsl500]

I had a bit of an issue removing the N10 Combination relay on my R129 500SL – one of those “did I really do that” moments….
So now I need a wiring diagram / cable colours for the relay socket pin connector positions… As I grabbed the relay and pulled the latch all the cables fell out of the socket….grhhh.

I think I have put them back as they came out – but with 3 rows of 7 connectors there are a lot of permutations!
It’s been a bit of a catalogue of errors that I wish I hadn’t started now. The original problem was that the wipers did not work on any position apart from fast speed. I addition they would park anywhere and the wash wipe washed but no wipe. Lights and indicators all worked fine.

The next error was that when I put the connectors back in I did not check all was as before by reinserting the relay - instead I sent it off for a service exchange item via carl at W140. When I plugged the replacement in all hell broke loose. Wipers came on as soon as the ignition was switched on apart from slow wipe where they stopped and the indicators are up the wall.. So it looks like I have a few wires wrong in the socket – or the replacement relay isn’t working as it should (though it came back with a comprehensive test sheet)

So I am a bit stuck now. I did find the cable colour codings on another site but I don’t seem to have all the same colours and their diagram showed 19 cables connected on the 7x3 array and I only have 18!
Help!!

 

[davidsl500]

As an update to my unanswered query, I have now resolved my issue… and there is a twist to the tale – literally!

I found a post on another forum from someone that had done similar and he posted up the cable colours / pin assignments. Interestingly he had only 2 blanks on his wiring and I have 3 in the 7x3 grid. Also a couple of colours on mine were different. ( I think he may have had 3 blanks as one of his colours were question marked.

Even when the connector housing is de-latched, the connectors tend to stay in the grid position as there are little plastic fingers around each female bullet that hold them in the formation. I checked my wire colours against his and to my dismay it looked like they were all correct – bugger!

Then I Spotted the twist ! I had made sure the relay carrier and connector block was the right way round before carefully feeding all the wires back in to it – but I got it 180 degrees out ! There must have been a natural twist in the harness and when the relay and carrier came away in my hand I hadn't noticed that the harness had straightened itself out and flicked 180 degrees!!

Now everything works absolutely spot on, wipers wipe, washers wash, indicators flash etc.. Interestingly, even my offside front fog lamp has started to work again which had been intermittent for years ( Not they are any good of course!) It would appear that no damage was caused by the relay wiring being reversed either – phew!

So for posterity, and in case I ever do it again I shall post the wiring colours for each pin just in case anyone makes the same error. My 1991 R129 500SL colours are listed. The pin numbers appear on the connector block and the relay itself.

1 Blank 8 BK YE GY 15 BK WH
2 GN BU 9 BK YE RD 16 GY BU
3 GN BK 10 GY BU RD 17 BK GN WH
4 BLANK 11 GY 18 BN YE
5 BLANK 12 BK BU WH 19 BK GN
6 BK BU GN 13 BU 20 BK
7 RD WH 14 GN 21 GY

The only difference to the other site is that they list Pin5 as being GN BK but with a question mark so that may be a red herring and it should be blank as mine.
They list Pin 6 as BK BU WH whereas mine is BK BU GN.
They list Pin 11 as GY WH GN whereas mine is just GY ( I have another grey as Pin 21 which agrees with theirs)

 

[S500+500SL]

This is a very old thread, but thank you @davidsl500 , you saved me a lot of grief today.

I made the exact same mistake while debugging indicator/wiper glitches. Put the plug back together 180deg out and all hell broke loose. No indicators, no hazards, wipers running at crazy speed then blowing the fuse. Had no idea I'd messed up so bad - pin #1 was no longer blank, but pin #21 was - doh.

All back together now and everything is running perfectly. Hopeful cleaning and reseating contacts has helped, as the N10 is now $1,000 with shipping here in New Zealand.

 

[malcolm E53 AMG]

Welcome!

The power of the internet - glad you got it sorted

 

[davidsl500]

This is a very old thread, but thank you @davidsl500 , you saved me a lot of grief today.

I made the exact same mistake while debugging indicator/wiper glitches. Put the plug back together 180deg out and all hell broke loose. No indicators, no hazards, wipers running at crazy speed then blowing the fuse. Had no idea I'd messed up so bad - pin #1 was no longer blank, but pin #21 was - doh.

All back together now and everything is running perfectly. Hopeful cleaning and reseating contacts has helped, as the N10 is now $1,000 with shipping here in New Zealand.

Hi and welcome. I'm glad my post was of help!

 

[Ronald A Perez G]

As an update to my unanswered query, I have now resolved my issue… and there is a twist to the tale – literally!

I found a post on another forum from someone that had done similar and he posted up the cable colours / pin assignments. Interestingly he had only 2 blanks on his wiring and I have 3 in the 7x3 grid. Also a couple of colours on mine were different. ( I think he may have had 3 blanks as one of his colours were question marked.

Even when the connector housing is de-latched, the connectors tend to stay in the grid position as there are little plastic fingers around each female bullet that hold them in the formation. I checked my wire colours against his and to my dismay it looked like they were all correct – bugger!

Then I Spotted the twist ! I had made sure the relay carrier and connector block was the right way round before carefully feeding all the wires back in to it – but I got it 180 degrees out ! There must have been a natural twist in the harness and when the relay and carrier came away in my hand I hadn't noticed that the harness had straightened itself out and flicked 180 degrees!!

Now everything works absolutely spot on, wipers wipe, washers wash, indicators flash etc.. Interestingly, even my offside front fog lamp has started to work again which had been intermittent for years ( Not they are any good of course!) It would appear that no damage was caused by the relay wiring being reversed either – phew!

So for posterity, and in case I ever do it again I shall post the wiring colours for each pin just in case anyone makes the same error. My 1991 R129 500SL colours are listed. The pin numbers appear on the connector block and the relay itself.

1 Blank 8 BK YE GY 15 BK WH
2 GN BU 9 BK YE RD 16 GY BU
3 GN BK 10 GY BU RD 17 BK GN WH
4 BLANK 11 GY 18 BN YE
5 BLANK 12 BK BU WH 19 BK GN
6 BK BU GN 13 BU 20 BK
7 RD WH 14 GN 21 GY

The only difference to the other site is that they list Pin5 as being GN BK but with a question mark so that may be a red herring and it should be blank as mine.
They list Pin 6 as BK BU WH whereas mine is BK BU GN.
They list Pin 11 as GY WH GN whereas mine is just GY ( I have another grey as Pin 21 which agrees with theirs)

Hello David:

I am fighting with my 1996 W140 here in San Jose, Costa Rica. I think I might have this issue as my electrician pull the module and I think he scrambled the cables.

I know this is a silly question, but my native language is spanish, altough I manage to speak and read english (more or less).

I have an issue with color descriptions. Would you please describe each color coding?? I know WH is white and YE must be Yellow, but I am completly baffled with BU, GN, GY, etc etc. I trully appreciate if you help me out with this and put the name beside each color so I can understand it. Sorry for asking this much, but believe, I have a lot in my hands trying to fix my car.

Have a great day and keep safe from Covid.

Ron

 

[davidsl500]

Hello and welcome. I think this chart covers most..

 

[MrShades]

Hi
New here but i for sure have this problem too.

The car is an 1992 300 Sl, R129. The 190 hp and not 24 valves

When i took off the 21 pin connector combination relay i pressed/pushed the connector where it is supposed to be pressed/pushed

When i did this the relay popped off easy except that the connector that is supposed to sit on the wires came off at the same time

Now i have about 16 loose wires that i eed to figure out where they go in the 21 pin connector

I have attached a picture of the wires on my 1992 300 SL, R129 seen from the left, the right, the front and from the rear

I have also attched a picture of the 21 pin connector and a drawing showing the numbers on the connector

So i need a wiring diagram that says that the black wire with a white stripe goes to pin 7 on the connector and so on

Or if any here have a 1992 300 SL, R129 that cane check/take pictures of the wires on the left side, right side and in the middle

Oh... Why did i take off the relay..

 

[LostKiwi]

Hi
New here but i for sure have this problem too.

The car is an 1992 300 Sl, R129. The 190 hp and not 24 valves

When i took off the 21 pin connector combination relay i pressed/pushed the connector where it is supposed to be pressed/pushed

When i did this the relay popped off easy except that the connector that is supposed to sit on the wires came off at the same time

Now i have about 16 loose wires that i eed to figure out where they go in the 21 pin connector

I have attached a picture of the wires on my 1992 300 SL, R129 seen from the left, the right, the front and from the rear

I have also attched a picture of the 21 pin connector and a drawing showing the numbers on the connector

So i need a wiring diagram that says that the black wire with a white stripe goes to pin 7 on the connector and so on

Or if any here have a 1992 300 SL, R129 that cane check/take pictures of the wires on the left side, right side and in the middle

Oh... Why did i take off the relay..

See the second post in this thread.

 

[MrShades]

I cant believe that i thought it only said 1 of the 3 grids..

This for sure helps me a lot.. It really made my day


So thanks a lot to everybody here

 

[davidsl500]

I cant believe that i thought it only said 1 of the 3 grids..

This for sure helps me a lot.. It really made my day


So thanks a lot to everybody here

I still remember the day when I did it all that time ago - 8 years has flown past! Yes, sorry about the formatting of the pinouts on my second post; I tabulated it in Word and it lost the formatting when I posted it to the forum. It took me a week searching for an answer and quite a lot of alcohol....... Glad it's still helping people after all this time!

 

[MrShades]

Thanks a lot for posting this davidsl500

You really saved my day

The reason why the wires came off the connector is because i pushed open what i thought was a "lock" on the connector when it really was the lock for the wires on the connector.
I can not understand how i managed to have all of the 17 wires come off the connector.
Just before i took off the connector i was thinking about taking a few pictures of the wires on the connector but off course i did not..

Do i remember correct that the side with 1 to 7 is on the right hand side of the car and the 15 to 21 is on the left side of the car?

Is this drawing i made correct?

 

[MrShades]

I theaded the wires thru the part of the connector today and everything is workings as it is supposed to

On slot 11 where the Mercedes diagram says the wire is grey/white/green the wire was grey on my car as well

Started the car and everything works as it is supposed to

Again thanks to davidsl500

 

[davidsl500]

I theaded the wires thru the part of the connector today and everything is workings as it is supposed to

On slot 11 where the Mercedes diagram says the wire is grey/white/green the wire was grey on my car as well

Started the car and everything works as it is supposed to

Again thanks to davidsl500

Well done that man. Now don't do that again!

 

[MrShades]

I can guarantee you that i will not loosen the part (marked with the red arrow)that holds the wires locked in the connector

So the part of the connector marked with a red arrow must not be touched since that is the part that locks the wires on to the connector.
You can see the 2 tabs marked with yellow arrows that is the what locks the wires to the connector (There are 2 tabs on each side)





Threading each wire to the correct position on the 21 wire connecor. Thanks to davidsl500 for posting where each wire is supposed to sit