Windscreen washer problem

I will try and help but I need some info.

Your car seems to be a "Q" plate, so what is it? Year, model and does it have headlamp washers? Ideally last 7 of your chassis number.

Tanks'n-Pumps and Headlights'n-Water!

Given what you say, it certainly appears that your set-up IS with headlight washers. There are two types of front tank. The one that has a detachable lid is for cars that do NOT have headlight washers.

1) The tank in the boot can never be filled to the brim...because of that airlock...it's just the way it's designed. So no worries there.

2) Check those sensors (there are 2.....1 on front bottle & 1 rear on the rear tank) are set vertical...if they are tilted off the vertical, they can give false readings.

3) Is the pump in the rear tank actually pumping water...or is it just making a noise?

4) You say the rear pump IS pumping.....and it's not reaching the front tank.....so if it IS pumping water, where's it going...........?

Good luck. Gerry will have some good ideas I'm sure.........

Agree with all that David but if you look at the Avatar pic, I do not see headlamp washer jet covers in the nosecone!

I have a similar problem (like always...)

First thing I'd check would be the front float, take it out and get a multimeter on there and make sure the resistance changes as switch closes. Then I'd check the rear pump by applying 12v directly to the motor (I bought a 12v probe to do this, it's great). This is also a cheeky workaround for filling your front bottle. This all assumes that the rear pump isn't pumping (you said it did?) But as Gerry says, if so where's the water going?

I did all these checks and everyting checked out but the the system still doesn't work, my suspicions are now turned to the relay.

Zitat von NickF;65387

I did all these checks and everyting checked out but the the system still doesn't work, my suspicions are now turned to the relay.

(Assuming you tested the working of the pumps and washer fluid level sensors)

The relay is easy to check and test. The relay is inside the blue SRA Module N6 in the front power distribution box. Take it out and pry the enclosure open (it's some sort of a click and fold design - you can open and close it without any damage). You'll notice two relays on the SRA Module board. The one furthest from the connector is the one controlling the trunk pump. The other one controls the headlight washer pump.

Put the module back in place (with the cover off), make sure the level in the front washer fluid tank is low enough to trigger the pumping from the rear tank. Have someone start the car and pay attention to the relay. If it moves but nothing happens, check the wiring from the relay to the pump. If it doesn't move, use a plastic stylo (or just anything that doesn't conduct) and operate the relay manually. The pump should work - otherwise you have two problems.

If the relay didn't actuate by itself, take the module out again and measure the voltage on pin 6 of the SRA Module socket while someone is starting the car. If it becomes high, the relay is broken. If it stays low the problem becomes more tricky and difficult to diagnose. The SRA Module is triggered by the A5 Relay Module (inside the left hand door sill - well at least for LHD cars, not sure how different RHD is). But that's a rather complex module with no available schematics. The A5 Relay Module has 2 plugs, one with thick wires and one with thin wires. The SRA Module is driven from pin 15 of the connector with the thin wires. Measure for connection between this pin 15 and pin 6 of the SRA Module socket. If that connection is ok, it's time to move on to the other side of the circuitry.

Unplug the trunk tank level sensor. Does the low washer fluid message appear? No? Wiring issue between the level sensor and the Body Electronics Module - or worse a failing Body Electronics Module. If the message appears, the rear tank level sensor circuitry should be ok.

The front tank sensor triggers the General Module. Make sure there's a connection between the front tank level sensor and pin 19 of X253 - at the General Module. If not, it's a wiring issue. If yes, uh-oh...

The General Module is yet another complex module without diagrams and it communicates with the A5 Relay Module over a databus of which no specifications are available. In other words, it's a bit unclear to determine the problem is in the General Module or in the A5 Relay Module. Perhaps a BMW GT1 "yellow head" might be able to diagnose the system at this point, but I have no experience with it. I have been intending to buy one since last year, but up to now I haven't done it yet so I'm not sure what and how detailed the system can diagnose...

PS: if you follow the ETM by-the-letter, you'll notice it contains serveral errors concerning the washer system.

Thanks for your help revtor. I'm going to mess with it tonight, but what I do know is that the headlight washers don't work either (but the motor is fine) and the low washer message does appear when I disconnect the rear float. I'll have a look at N6 but I guess it's unlikely that both relays are shot. The rest of your advice freaked me out a bit but I need to stop being a woos

Had a quick look at my relays and the position where N6 should be had what I think is a different relay in there. It was large and blue and had the part number 61 351 383 417, realoem describes it as Relay Module 2 (handy!) Realoem claims the headlight cleaning module is 63 351 389 002. The last owner was a major cowboy so he may have replaced the relay with one that was "close enough"!!!. I'd guess this was my problem, do you think my relay is wrong or is just a replacement part number? There doesn't look any way to take the relay apart either.

I don't know the part numbers out of my head. I'll have a look tomorrow if I don't forget. I should have pictures of it somewhere, but I can't find 'em. Dammit

The color is right though. It's a blue module. Assuming it's the right module: Put the module on its top with the contacts facing upward. One side of the bottom has an extension of the blue plastic cap. That part can be flipped open (pry a fine jewel screwdriver or knife underneath it on the sides and lift). Once it's opened you can pull the contents out. If I remember correctly, the module contained two transistors, several resistors and two open relays.

There are two identical (same part#s) modules next to each other, the other blue one is on the engine side of where the N6 should be. The modules looks like this.... 8er.org/forum/index.php?attachment/9164/

1383417 is ex ETK the relay module for the pressure adjustment of the windscreen wipers and the number count for this is 1 in the car! It is located as K12 adjacent to N6.

As can be seen from the schematics they´re "not quite" the same but I am by no means anyone to really know what is going on in there

N6 can be found as headlamp cleaning module 1389002 (currently 52 EUR) with the exact same pinout. The pinout if those relays is shared with others too - no wonder someone might think that they fit...

Cheers
Reinhard

thanks Reinhard. The previous owner was quite a piece of work, he fixed a loose connection in the headlight with a sock, i'm not joking. I think we should start insisting on background checks as part of e31 ownership .

I'll buy a new relay and see how i get on.

Ebay 330335865366

Much cheaper than new. Worth a try. If he doesn´t ship to the UK I will.

This one in the UK: Ebay 380081918682
20 Quid shipped

Cheers
Reinhard

thanks again Reinhard! I thought the module was supposed to be blue?

Yeah, I was pretty sure it was a blue module, but maybe my memory is fading or perhaps I'm going color blind .

If the part number matches, you should be fine. The rest of my instructions should still apply, but if there's really an incorrect module at the N6 position, your issue is most likely resolved after installing the correct SRA module.

Unfortunately it turns out that the sock in your headlamp may have been OEM after all

I just snapped a few pictures of my fusebox and lo and behold:

I guess that means "back to the drawing board" as those relais´are obviously "quite the same". At least you know now that it won´t hurt to swap them over.
Did you check Fuse 27?

Cheers
Reinhard

If you want to know what's inside...

Bottom side. Note the small overlap of the blue enclosure on the bottom. On each side are two small notches. Insert a small flat jewel screwdriver underneath those and lift.

The cap should now fold open, unlocking its contents. To take the board out, squeeze the side of the enclosure a bit (the side with the model number printing and the opposite side) and pull the board out.

The magic stuff inside the SRA module. Nothing magic actually. Just two relays and two transistor drivers - one for each relay. If you'd follow the traces and draw a diagram, you'll notice the ETM diagram is wrong (don't worry, the wiring in the car is correct - the ETM is wrong at many places). The relay furthest away from the contacts is the trunk washer fluid pump (left on the picture).

Now since these are open relays, you can operate them manually. Reinsert the module back in the front power distribution box (with the enclosure off obviously). Use an isolated thingy to operate the relay (the top one when installed). You can use your finger, just 12 V, nothing dangerous, but I prefer to keep my fingers of bare naked copper. Fingerprints leave an acid residue that may corrode the copper. If I'm not mistaken, it should already work without ignition, but if it doesn't, try the ignition at I (the engine does not have to run).

When you operate the relay, you should hear the pump in the trunk. Don't leave it activated too long. It's a powerful pump and the front reservoir is filled much faster than you'd think. If unsure, have someone check the front reservoir while you operate the relay.

If the trunk pump works this way, the wiring to the pump is ok. Just pick in on my instructions I posted earlier.

Warning: At no occasion should you operate the bottom relay while the hood is open and the front power distribution box exposed. The bottom relay operates the headlight washer pump. That's a very powerful pump and with the headlights down, the hood open, and the front power distribution box exposed, everything under the hood will be soaking wet!

Putting the module back together is just the reverse. The board fits only in one way. No chance of getting it all wrong. Push the blue flap in place before you seat the board all the way down.

Finally got round to looking at this (although still couldn't spend long on it). Took the relay apart and it doesn't move on it's own when the car is switched on. But when i manually move the top relay the pump works and fills the front tank. I thought i'd check the level switch on the front tank and despite changing it twice for brand new OEM switches it is now failing to change resistance when it is closed manually out of the tank. When it was new (about 500 miles ago) when the switch was closed it was open circuit, now there is no difference between open and closed. Is something breaking the switches? Doesn't sound right.... Anyway, I shorted out the connector that connects to the switch and still the relay didn't move. I replaced the SRA module with a red one that i got from ebay and no difference, and i switched the two blue modules around prior to that so i think i can rule bad relays out.

I can't find the front tank level switch in the ETM at all? Does the fact that the headlight washers do not work either give us a clue to where the problem lies? I know I have more (too complicated for me ) instructions to go through, but i was hoping that this new info may give you a clue before i starting down the multimeter route.

Zitat von NickF;66301

I can't find the front tank level switch in the ETM at all?

I forgot what year your car is of, but in the '91 ETM the washer fluid level switches can be found on page 6210.0-06. In the '95-'96 ETM it's page 6210.0-08. Switch S64 hooked up to connector X109 is the front level switch, S136 hooked up to connector X10046 is the trunk level switch.

Please note the ETM is wrong on this page. The front level switch is drawn correctly, but the trunk level switch has the contact labels switched. Just as with the front level switch (1) indicates sufficient level and (2) low level.

Thanks Revtor - got it now. It's a 91 BTW. Am i right in assuming that shorting out X109 should make the system think that the front tank is low? I need to rule out my dodgy level switch.