A 150 no front wipers.

[toolman1954]

Hi,
Re .... A150, 2007, VIN WDD1690312J449506
The wipers have stopped working on the O/H's little A150.
Her local garage was able to check the fuse and to test the wiper motor and confirm it works ok, but not rectify the fault. So at the moment she has no wipers till I go back up Scotland at the end of the week and try to resolve the issue.
I suspect that the wiper / combination switch has packed up and I would like to buy one off of ebay, but need a part number, to make sure I get the right part.
So, could anyone help with a part number for a wiper stalk for a 2007 A150 please.
Also please, it would be handy to get a portion of the wiring diagram that has fusebox to wiper stalk to wiper motor on it, so I can trace the wiring, just in case there is a break somewhere.
Thanks very much

ADD...as the rear wiper still works, I did suggest in case of rain she just drives it in reverse, but that didn't go down too well......"Off" was the second word she used!

Steve

 

[Codger49]

A169 545 02 10 - Turn Signal Switch (think its usually called Combination Switch, it is in WIS)

In case, you haven't already come across it, Lofty's A class website might be of some use: Lofty's homepage. A-class info, Mercedes Benz 'A' Class W168 W169, Holidays in Scotland, Home Wine making, Kittens to Cats', Solar panels PV, Canada Rockies, Orchids, .Alaska 2015, Solar Thermal, How to look after you Orchid plants,.

Will have a look at WIS to see if there's a suitable wiring diagram.

 

[Codger49]

Think you may have to put the A class on a Star to fully understand what has happened.

The combination switch is connected to the Steering Column Module which uses Canbus to communicate with the SAM control unit which then controls the wiper motor.

 

[brucemillar]

Something to keep in mind. The front wipers on some Merc's, have a safety cut out. this stops them operating, if it detects the bonnet, or a door is open. All other wipers will continue to operate normally.

Maybe worth checking your door pin switches are fully closed and working correctly, along with the bonnet switch wiring etc. Give the bonnet a good hard close (slam) A good test may be to try the windscreen washer jets. If they do not activate? Then it may well be that the system thinks a door is open.

 

[Codger49]

I can send you a pdf of the SAM and wiper motor wiring diagram, just need to PM me with your email address.

 

[toolman1954]

Gentlemen,
Thank you both for your input, and suggestions.
Codger, .......thanks for the part number, seems only a new one from MB @Newcastle has the right part number, but your mention of the front SAM had me searching on Ebay only to find that the SAM is also the fuse box. So that gives me more hope for fault finding before I have to go somewhere with a Star machine. Where I live in Scotland there are no close by Indies with a machine, nearest would be MB Edinburgh Newbridge.
Yes please to your offer of a wiring diagram I will pm you.

Bruce, ....I had never heard of the safety cut out before, if only that can be the cause, then an easy fix, but knowing my luck it will be something more complex. However any others reading this thread will no doubt be as enlightened as I was by your words of wisdom. Good useful post.
So onwards and upwards. I wont be back up Scotland till the end of the week, and have o/h's computer to fix also, so may be Monday before I get to have a look at her car. Armed with the I980, the wiring diagram, my Fluke and trusty old light up pointed probe, I will see what I can find.
I have already studied Loftys A169 notes, and there is a picture strip down of the steering wheel and other allied components, so that will be very useful. Also useful to note is that with a new stalk you get a little red "pint" (sic) to lock the steering sensor, while you take it all to bits. Cars are so complex these days and my brain is getting old.
Thanks again

Steve

 

[toolman1954]

Just a Bit of An Update.
After I arrived back into Scotland. I found out that she (o/h) had only given me half a story, not only were the wipers still not working, also she had an SRS warning on the dash.
I plugged in the Icarsoft code reader and that came back with a raft of fault codes, too many to list here.
After some heavy Google searching, it seems that ...no wipers, a SRS message and the fag lighter not working are all symptoms of a relay on the front SAM going bits up. So, good job I had not gone out and bought a new multifunction switch for £100-00.
Armed with the wiring diagram kindly provided by Codger, ....Thank you ... I tested the 25 amp fuse at 39e and found no volts. This fuse provides power to the 2 relays on the SAM. Relay K100kf (wipers on/off) and relay K100ke (wipers stage 1/2 ).
Without power to these there was no power going to the wiper motor. The garage she used had already tested the wiper motor and said that it was working. Now I needed access to the front SAM and the relays.
Quelle Batarde !!!! What a job this was. Location of the front Sam is under the front passenger carpet, just below the rear of the Glovebox.
Carpets in the A Class are backed with a large amount of foam sound deadening material. After struggling for some time on my arthritic knees, I gave up and used a Stanley knife to cut the carpet across the natural body line of the floor pan. Then it was easy to slice through the rubbery foam and remove the carpet.
Revealed were 2 banks of relays on the front SAM unit.
I took out the 2 yellow relays K100ke (wipers 1/2 ) and K100kf (wipers on/off)... Tyco A0025421419 and took them to bits.
Apart from some light pitting on the points, they measured ok on the meter and clicked shut ( to let the heavy duty current flow through the relay ) when a 9 volt battery was applied to them, so they seemed to be working, and back in they went.
Next I checked the 50 amp fuse at 69 on the fusebox, and confirmed power to that. This fuse feeds a grey relay K100kb ( circuit 15R ) this relay then feeds the 25 amp fuse at 39. So I pulled this relay and also a similar one next to it K100ka, another 15R circuit relay. When tested with the 9 volt battery there was no clicking from this relay. Halleluja .... getting somewhere. I checked the other grey relay I pulled out, similar part number, and that clicked fine.
So, the culprit all along was Tyco A0025422619 (Mercedes general purpose overload relay.) So the next job was get another relay, and there are no breakers round here, so it was an Ebay job and a replacement relay coming in a couple of days.
So... still no wipers and she had to get to work tonight, and today here in Scotland we have had snow, sleet, hail, and as I didn't fancy turning out at 4-00 am to fetch her, I took the over off of the broken Relay. Cleaned the contacts, bent the wee spring a bit, and click click it was working. So I refitted the relays turned on the wipers and there was just a twitch from the wipers but no actual movement. However the SRS light on the dash had magically disappeared.
I tried moving the wipers manually and they seemed very stiff. Had the cause of the relay going been the wipers seizing up? They were devoid of grease and up here I do not have a tin ( yet ) of spray grease.
Next job was to take off the wiper arms which were both seized on. Fortunately, I had found an old / new stock, simple 2 legged puller which was destined for my Ebay shop. I must have had this puller for a good 20 if not more years. Today it was the hero,( and me also, so she said !) and pulled off both wiper arms.
After giving all the linkage a good soaking with some excellent spay oil (WM40 not WD40! ) I had some working wipers...... I know this is all boring, but perhaps one day in the future someone may be grateful for my ramblings .
Next instalment ...(yes there will be ), to include a portion of wiring diagram and relay positions to assist the casual reader..
Note also, that as a B Class has very similar wiring and relays, this repair would also apply to them.

Steve

 

[brucemillar]

Steve
I have to say I admire your perseverance here. Not east as I know that these particular models are tight on space (to say the least). Well done you Sir. Good job and helpful post.

Rather oddly. Today, I have to return a large parcel (Merc Parts) to Leven, from Kent, via our Postal network.

 

[toolman1954]

Bruce,
Thanks for your words of encouragement. I don't mind electrical problems as long as it does not involve laying upside down in the front footwell. My days of this sort of malarkey are done with, as is laying under cars and pulling gearboxes out. Being perhaps twice your size does not make it any easier squeezing into an A class. I am hoping that the replacement relay will solve the problem as I do not relish getting the SAM out.
On point 2, there is not someone round here that breaks Mercs is there?
The area seems pretty devoid of car breaker yards, although having not been up here that long, there may be some hidden away I do not yet know about. Thinking about it , there is a man, whom I often chat to, who walks his dog down at the beach when I take mine, he seems to be a font of knowledge of the area. Perhaps I will ask him.

Steve

 

[John N]

Burnside Motors have at least 2 A Class advertised online! Unsure if they are trying to sell whole or for Parts!

 

[oldguy57]

Admiration for the way you went about that job Steve! Its very satisfying to solve this type of problem without much cost.

 

[toolman1954]

O.k. Time to put this to bed.

John N......Burnside seem just to have some damage repairables for sale, all the cars for breaking seem to be at SCB, at Newbridge, which is other side of the bridge around M8/M9 Junction. Seem to have lots of vehicles there to be broken.

So eventually the replacement relay came Friday, my bodge job on the broken one did not last too long, so it had been another 2 days without wipers .
Tested the relay, fitted it, and all worked fine, just a 2 minute job, yet hours of dismantling and fault finding.
We have wipers, no SRS light and the fag lighter works. At the moment I have not refitted the carpets "just in case "!

I have uploaded to P/B wiring diagrams and other trivia just in case it will help some other poor lost soul.
Apologies if this has been a little long winded.

Not Quite Over.... I plugged in the MB2 Diagnostic just to check everything was O.K. and " No connection to ECU " came up. Grrrr.
Back to the fuse diagram, fuse 16 controls diagnostics. Tested the fuse for 12 volts and only power to one side, pulled the fuse, tested it using the meter and it now read across ??
Replaced fuse, diagnostics working, and no errors. At least no need to replace the SAM !! and must have saved a few hundred quid.

[/URL][/IMG]

 

[219]

Bruce,
Thanks for your words of encouragement. I don't mind electrical problems as long as it does not involve laying upside down in the front footwell. My days of this sort of malarkey are done with, as is laying under cars and pulling gearboxes out. Being perhaps twice your size does not make it any easier squeezing into an A class. I am hoping that the replacement relay will solve the problem as I do not relish getting the SAM out.
On point 2, there is not someone round here that breaks Mercs is there?
The area seems pretty devoid of car breaker yards, although having not been up here that long, there may be some hidden away I do not yet know about. Thinking about it , there is a man, whom I often chat to, who walks his dog down at the beach when I take mine, he seems to be a font of knowledge of the area. Perhaps I will ask him.

Steve

There used to be a huge yard in Kirkcaldy , and a smaller one which still has a couple of Adenauers - not from the area and while I could find my way back to them I couldn't tell you names or addresses . Then there's one in Lochgelly , which is the same company as Sports Car Breakers over at Newbridge ( who had several A Classes last time I visited ( SCB ) a few months back ) , Watson's in Inverkeithing ( now pull a part ) . Over here in Glasgow there is Stewart's autobreakers in Muirhead , who have a couple of dozen Mercs in - I was there on Friday getting parts off a W140 for my R129 , they have lots of W203 , W210 , W211 ( including a S211 with factory Oris towbar) and a number of A Class ( at least 3 or 4 the other day ) . There are 3 yards in Paisley who usually have Mercs , one in Yoker , Shewalton Autobreakers just outside Irvine and Barry Devlin's yard at Knockentiber , just outside Kilmarnock . So there are yards in the area .

 

[219]

Incidentally , I was just in this part of the forum as the wiper in my R129 started acting up this week and working when it felt like it .

Knowing that these problems are often dry solder joints within the relay modules I proceeded to tap each relay with the handle of a screwdriver , on discovering the culprit which caused the wipers to come on when I tapped it , I pulled it out and opened it up to find the tracks burned away in one area of the board .

A bit of time with the soldering iron and some fine wire out of a piece of CAT5e cable and I had bridged from one component to the next on each side of the burnt out bits and got everything working again . However I wasn't entirely happy with the job so thought I'd visit that W140 , from which I've had a few parts already , my main prize being the wood/leather steering wheel which I know Merc want well into four figures for but the guy in the yard sold me for £20 Alas , the relay wasn't there , but I did get the two sun visors which are very similar to my R129 ones ( one of which the flip up mirror cover was broken on ) and the guy took a fiver for the pair , but if you look on eBay people always want £150+ each for them !

I like the yards around here !

While there were a few 129 wiper relays on eBay , I phoned my dealer and ordered a new one at £159 , since a used one at £120 on eBay might be no better than the one I repaired myself .

I also greased the jumping mech on my wiper , which was OK , and the burnt tracks were on the low current control side so unlikely that was a problem - must also do the one on the 190 too .

 

[tonysmb]

Toolman. Top man, thanks for posting this thread. To me, this is what these forums (fora?) are about.

 

[AndyBroadhead]

O.k. Time to put this to bed.

John N......Burnside seem just to have some damage repairables for sale, all the cars for breaking seem to be at SCB, at Newbridge, which is other side of the bridge around M8/M9 Junction. Seem to have lots of vehicles there to be broken.

So eventually the replacement relay came Friday, my bodge job on the broken one did not last too long, so it had been another 2 days without wipers .
Tested the relay, fitted it, and all worked fine, just a 2 minute job, yet hours of dismantling and fault finding.
We have wipers, no SRS light and the fag lighter works. At the moment I have not refitted the carpets "just in case "!

I have uploaded to P/B wiring diagrams and other trivia just in case it will help some other poor lost soul.
Apologies if this has been a little long winded.

Not Quite Over.... I plugged in the MB2 Diagnostic just to check everything was O.K. and " No connection to ECU " came up. Grrrr.
Back to the fuse diagram, fuse 16 controls diagnostics. Tested the fuse for 12 volts and only power to one side, pulled the fuse, tested it using the meter and it now read across ??
Replaced fuse, diagnostics working, and no errors. At least no need to replace the SAM !! and must have saved a few hundred quid.

[/URL][/IMG]

So I had the same problem. Changing the relay has got me my wipers back. Now the bloody thing will not start. Any help greatfully received!

 

[toolman1954]

Hi,
Well .. bit of a thread revival.. but I am pleased you have your wipers working.
Car will not start, you say so we need a bit more information from you.
Key into the ignition,....does everything light up?...When you turn the key, does the starter motor turn the engine over? ...In your quest to repair the wipers, what else have you touched? Have you looked at all the fuses to see if one has blown? What was the cause of the overload relay failing ? On her car the wiper mounts had seized up from lack of lubrication, and caused the overload relay to fail.

Steve.

 

[AndyBroadhead]

Hi,
Well .. bit of a thread revival.. but I am pleased you have your wipers working.
Car will not start, you say so we need a bit more information from you.
Key into the ignition,....does everything light up?...When you turn the key, does the starter motor turn the engine over? ...In your quest to repair the wipers, what else have you touched? Have you looked at all the fuses to see if one has blown? What was the cause of the overload relay failing ? On her car the wiper mounts had seized up from lack of lubrication, and caused the overload relay to fail.

Steve.

Steve. Thanks for your reply. All I’ve done is checked / changed relays. Yesterday when I followed this thread to diagnose the faulty relay swapped over two of the A0025422619 relays. When they were swapped the wipers worked but the car didn’t start. Swapped them back and the opposite. Started but no wipers.

I’ve bought a new relay and now the car has wipers. The car also started.

When I’d assembled everything back the car didn’t start.

Now when I say start; the key goes in, ignition on, dash lights, radio etc all on. When I turn key to position 4 to start there is nothing. Engine doesn’t turn over. Nothing at all!!

 

[AndyBroadhead]

Steve. Thanks for your reply. All I’ve done is checked / changed relays. Yesterday when I followed this thread to diagnose the faulty relay swapped over two of the A0025422619 relays. When they were swapped the wipers worked but the car didn’t start. Swapped them back and the opposite. Started but no wipers.

I’ve bought a new relay and now the car has wipers. The car also started.

When I’d assembled everything back the car didn’t start.

Now when I say start; the key goes in, ignition on, dash lights, radio etc all on. When I turn key to position 4 to start there is nothing. Engine doesn’t turn over. Nothing at all!!

I’ve visually checked all the fuses. There didn’t appear to be any reason why the relay had failed.

 

[toolman1954]

Hi,
Now excuse me if I have not gotton this correct ( I am getting old ) , but at this moment in time your engine will not fire up into life... starter is doing nothing.
I have appended below, the fuse box diagram and also the relay diagram. One thing I notice is that the engine starter relay is M and the engine circuit relay is at L. Both of these are just below the relays you have replacing, have you knocked these out ?
My approach to this would be to test all the relays involved in getting the engine started. Do you know how to test a relay? Just a 9 volt battery across 2 of the terminals and you should hear a click click sound as the contacts shut together, which then provides a circuit between the other 2 contacts.
I am also unsure of what occurred when you swapped relays and the engine did start, and also the original cause of the 1st relay failing.
I would have taken this to bits to see what had happened as generally relays are pretty reliable, only failing when subjected to a heavy current overload. If the contacts were very burned or the coil melted then you had a direct short somewhere, which you need to investigate and repair. Wipers shafts seizing up for instance.
A visual check of the fuses is often not enough when fault finding, you need a multimeter or a simple light up test light prod to check for voltage at both sides of the fuse holder.
I am sure you will find it is something simple, however the simple things often take time to find.
Below are copies of your fuse box and the relay box, I hope these help.

Steve.

1. Fuse allocation chart
2. Fuse box

No.
Fused function
A
1 Stop light switch 10
Valid for code (U62) Light and vision package:
Stop light switch
5
2 Heated rear window 25
3 Instrument cluster
EIS [EZS] control unit
7.5
4 EIS [EZS] control unit
Electric steering lock control unit
15
5 Valid without code (580) Automatic air conditioning and without code (581) Comfort automatic air conditioning:
HEAT control and operating unit
Valid for code (580) Automatic air conditioning:
AAC [KLA] control and operating unit
Valid for code (581) comfort automatic air conditioning:
Comfort AAC [KLA] control and operating unit 7.5
6 Left fanfare horn
Right fanfare horn 15
7 Fuel pump relay
25
Valid for model 169.090:
DC/DC converter control unit
5
8 Overhead control panel control unit 25
9 ESP and BAS control unit
40
10 Blower regulator/interior wiring harness connector 40
11 Valid for engine 266:
Circuit 87 relay, engine 30
Valid for engine 640:
Circuit 87 relay, engine
40
12 Steering column module
Multifunction steering wheel 5
13 Left front door control unit
25
14 Right front door control unit
25
15 ESP and BAS control unit
25
16 Data link connector
PTS control unit
10
17 Rotary light switch
5
18 Valid for transmission 711, 716:
Backup lamp switch
Valid for model 169.090:
A/C compressor control unit
BKGN Energy monitoring control unit
Vacuum pump 1 control unit
Vacuum pump 2 control unit
7.5
19 Micromechanical turn rate sensor AY pickup 5
20 Restraint systems control unit
7.5
21 Starter relay 30
22 Instrument cluster 7.5
23 Washer nozzle heating
7.5
Valid for engine 640 as of 1.9.08:
Fuel filter condensation sensor with heating element
20
24 Electric power steering (ES) control unit
7.5
25 Stop light switch
ESp and BAS control unit
7.5
26 Valid for transmission 722:
Electronic selector lever module control unit
7.5
27 Valid for transmission 722:
CVT (continuously variable automatic transmission) control unit
10
28 Rotary light switch 5
29 SAM control unit
30
30 Circuit 87F relay
25
31 Central gateway control unit (vehicles up to 30.11.05)
Rotary light switch
Automatic light switch daylight sensor
Rain/light sensor
5
32 Valid for engine 266:
ME-SFI [ME] control unit
Valid for model 169.090:
Energy monitoring control unit
7.5
33 Radio
Radio and navigation unit
COMAND operating, display and control unit (Japan)
15
34 Left rear door control unit 25
35 Right rear door control unit 25
36 Cell phone separation point
Trailer control unit 7.5
Trailer control unit
PTS control unit
10
37 Restraint systems control unit
Front passenger seat occupied recognition sensor
Front passenger seat occupied and child seat recognition sensor 7.5
38 Front cigar lighter with ashtray illumination 25
39 Wiper motor 25
40 Overhead control panel control unit
7.5
Roof motor
25
41 Liftgate wiper motor
15
42 Glove compartment illumination with switch
Left and right vanity mirrors illumination
Footwell illumination switch (driving school package)
Pedal operation monitor switch (driving school package)
VICS+ETC voltage supply separation point (Japan)
7.5
43 Valid for engine 266:
Terminal 87M1 e connector sleeve 15
Valid for engine 640:
Terminal 87M1e connector sleeve
7.5
Valid for model 169.090:
Vacuum pump 1 control unit
20
44 Valid for engine 266:
Terminal 87M2e connector sleeve 15
Valid for engine 640:
Terminal 87M2e connector sleeve
20
45 Valid for engine 640:
CDI control unit
Valid for model 169.090:
Vacuum pump 2 control unit
25
46 Telephone control unit, (Japan)
E-net compensator
Universal Portable CTeL Interface (UPCI [UHI]) control unit 7.5
Bass module speaker (Japan)
25
Amplifier for sound system
40
Valid for model 169.090:
Charging control unit
5
47 Telephone control unit, (Japan)
Universal Portable CTEL Interface (UPCI [UHI]) control unit
Cell phone separation point
Voice control system (VCS [SBS]) control unit
Valid for model 169.090:
Charger 1
7.5
48 ATA [EDW]/tow-away protection/interior protection control unit
Alarm signal horn with additional battery
Valid for model 169.090:
Charger 2
7.5
49 Upper control panel control unit
Left front seat heated cushion
Left front backrest heated cushion
Right front seat cushion heater element
Right front backrest seat cushion heater element 25
50 CD changer
Media interface control unit
Digital TV tuner
Digital Audio Broadcasting control unit
VICS+ETC voltage supply separation point (Japan)
7.5
Valid for government vehicles:
Roof light bar
Circuit 30 connector sleeve
30
51 Valid for model 169.090:
Cooling fan
Low temperature coolant pump
10
52 VICS+ETC voltage supply separation point (Japan) (vehicles up to 31.5.06)
Valid for model 169.090:
Electric drive control unit
5
Spare (vehicles as of 1.6.06)
7.5
Emergency call system control unit (USA) (vehicles up to 31.5.06)
7.5
53 Rear cigar lighter with ashtray illumination
Interior socket
30
54 Amplifier for sound system
Bass module speaker
25
Valid for model 169.090:
Electric drive control unit 5
55 Left front lamp unit (Bi-xenon)
Right front lamp unit (Bi-xenon)
7.5
Left front lamp unit (Hi-xenon)
10
56 Spare 10
Right front lamp unit (Hi-xenon)
10
57 Trailer hitch socket (13-pin) (vehicles as of 1.6.05)
15
Audio gateway control unit (Japan) (vehicles up to 31.5.05)
25
SDAR control unit
Emergency call system control unit (USA)
7.5
58 Trailer control unit
Valid for model 169.090:
Vehicle gateway control unit
25
59 Trailer control unit (vehicles up to 31.5.05)
Trailer hitch socket (13-pin) (vehicles as of 1.6.05) 20
Valid for model 169.090:
Battery management system control unit 1 5
60 Driver seat connector block
20
61 Front passenger seat connector block 20
62 Circuit 15 relay (2) (SA: xenon, cell phone) 25
63
Spare (vehicles up to 31.5.05)
-
Audio gateway control unit (Japan) (vehicles as of 1.6.05)
Valid for government vehicles:
Roof light bar
25
Emergency call system control unit (USA) (vehicles as of 1.6.05)
SDAR control unit
7.5
Valid for model 169.090:
Battery management system control unit 2
5
64 Valid for engine 266:
Air pump relay
40
Valid for engine 640:
Engine wiring harness/engine compartment connector
Glow time output stage
80
65 Electric power steering (ES) control unit
80
66 SAM control unit
60
67 Circuit 15R relay (2) (SE) 50
68 Valid for engine 266.920 and engine 266.940 with transmission 722:
AAC with integrated control additional fan motor 50
Valid for engine 640.940, 640.941, 266.960, 266.980 and for engine 266.920, 266.940 with (Trailer hitch):
AAC with integrated control additional fan motor
60
69 Circuit 15R relay (1)
50
70 Circuit 15 relay (1) 60
71 Valid for engine 640:
PTC heater booster 150
72 Circuit 30 connector sleeve
Special vehicle multifunction control unit (SVMCU [MSS]) (Taxi)
60





No.
Fused function
A
80 Reserved for special-purpose vehicles 30
81 Reserved for special-purpose vehicles 30
82 Reserved for special-purpose vehicles 30
83 Reserved for special-purpose vehicles 30
Relay
A Circuit 15R relay (2) (SA)
B Circuit 15R relay (1)
C Fanfare horn relay
D Heated rear window relay
E Wiper stage 1/2 relay
F Wiper ON/OFF relay
G Circuit 15 relay (1)
H Backup relay
I Air pump relay
K Fuel pump relay
L Engine circuit 87 relay
M Starter relay
N Circuit 87F relay
O Circuit 15 relay (2) (SA: xenon, cell phone)