Windscreen / Headlight Wash Problems

[M3KUK]

Hi, I have a 1989 325i 4 door with headlight wash and intensive cleaning and a few problems! The intensive clean has never worked, there is power to the stalk and the pump motor works if I swap it's connection with the std wash motor.

There is a leak from either the headlight wash or std wash as the tank empties itself in a day or two.

The intensive tank is full and it never drops.

First off, has anyone got a diagram of how all 3 systems integrate with each other, connections etc?

Here's my take on it, the wash water is pumped from the main tank, splits into a tee with one half going to the headlights, via a one way valve for each light. The other half of the tee goes to a combined one way / tee valve at rear of bonnet for the windscreen washers. I am ordereing said valves etc from Cotswold which should cure the leaks.

The question is, where does the intensive wash fit in?

Any help please? I have a 320i Cabriolet but it has just the basic windscreen wash.

[M3KUK]

Anyone help?

[joew23]

Hi,

in my experience with the HLWW system. it seems to almost always be connections on the electrical side preventing operation. unless the wiper motors are seized. even if they are the pump should still latch on and spray the headlamps.

The T-pieces you mention also contain non-return valves. I have seen these become stuck open allowing the washer jets on the headlights to siphon the entire washer tank.


the first electrical connection i suggest checking is where the whole system picks up power. which is on the passenger side behind the headlight. obviously the system only works when the headlights are on.

hope some of this may help?

[Brianmoooore]

There is one pump in the smaller tank, for intensive wash, and two pumps in the larger tank - one for 'normal' screen wash, and one for headlamp wash.
The pipes from the intensive wash pump and 'normal' pump run parallel with each other up into the centre of the bonnet, where they each go to twin outlet/one way valves, and from there, via short hoses, to two 'Y' pieces, where the two flows are combined, and go to each washer jet.
If you go to Tech Help, then wiki, then Retrofit guides, then Headlamp wash/wipe system, and finally either of the BMW instructions, you will find diagrams of how the pipes are arranged.
The headlamp wash pipe goes from the pump to a tee piece, and then to two individual non return valves about six inches from each headlamp washer jet. These non return valves often fail, and when they do, the washer tank will empty by gravity, either through the vent hole in the faulty valve, or through the washer jet.
The intensive wash electrical circuit is fairly simple. There is a purple/black wire on one terminal of the pump, which should have 12 volts + on it when the ignition switch is in positions 1,2 or 3. The other terminal of the pump has a brown/grey wire which goes, via three plugs and sockets, to the wiper stalk, where the brown/grey is earthed when the intensive wash button is pushed. This wire branches into the socket for the wiper module in the fusebox on the way, where it connects to the PS terminal, to trigger the wipers and maintain the intensive wash when the button is released.
Even if there is a fault in the wiper module, the intensive pump should work when the button on the wiper stalk is pushed.
There is a reasonably accurate wiring diagram in the Haynes E30/34 manual, 1948, which is available on line.
The headlamp wash motor is controlled entirely by a switch inside one of the headlamp wiper motors, so will never work if that motor (the one with four wires) is seized. Occasionally you may come across a headlamp wiper motor that has seized part way through its wipe sequence, and in this case, the wash motor may run continuously until a plug is pulled.
The wipe sequence for each headlamp wiper motor is also self contained. There is a purple/black wire to each motor which is live with ignition on, and a black/yellow wire from the control module on the side of the washer tank. This control module just produces a short (around half a second or so) 12 volt + pulse, which just starts the motors off. Once they have been started, each wiper's complete sequence and subsequent parking (and the washer) is controlled by internal cams and switches.

[Gert_8]

Thanks Brian - my head hurts now...

[M3KUK]

Thanks guys, gonna tackle this if it ever stops raining!
The passenger side headlight wash 1 way valve has failed, as the
water sprays out of the pinhole in the side when washing.
I have the Haynes manual, so will take a look at that too.

[M3KUK]

Bit more progress, replaced all the one way valves etc. Headlight wash now working and windscreen wash too. When you wash the windscreen though, the intensive tank 'bubbles up' as if fluid is finding it's way back into the tank from the std wash. Intensive wash button still not working but power at the pump and if you ground the side connected to the stalk push the pump operates! Thinking faulty wiring going back to the stalk push.

[Brianmoooore]

The tee valves on the underside of the bonnet on the end of the pipe from the intensive pump must be leaking internally. May just be as a result of lack of use, if you're lucky.
Where are you earthing the grey/brown wire to make the pump run? At the plug and socket clipped to the steering column?