[T6_modified] Headlight washer - manual activation

[mmi]

From factory headlight washer does it's job together with windscreen washer whenever the headlights are on, thus always a burst for the first windscreen wash after engine startup, then a burst for every 10th windscreen wash.

Did some investigation if the washer could have been activated the same way as on more modern platforms - long press of windscreen washer (or even "double click"). Seems that that kind of functionality isn't available in T6 BCM.​

I wanted have some more control - especially in subzero temperatures - actually headlight washer is rarely needed.

Now -

1. After engine start headlight washer relay is disconnected by "bistable relay" contact being "normally open".
2. Pressing a button on dash "activates" the headlight washer - relay closes and turns on yellow light on switch
3. To run the headlight washer - run windscreen washer with headlights on - the headlights washer runs every time when windscreen washer is triggered
4. Another press of the button deactivates headlight washer

For other switch locations see attachment for part numbers. Switch illumination (B342) taken from an adjacent switch.
Reference wiring diagram --> https://t6forum.com/downloads/washers-wipers-wiring-diagram.128/

Spoiler: Bistable relay, etc

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Spoiler: Measurements

 

[Robert]

Lovely mod Matti .
Well done .

 

[Robert]

By the way, have you played with VCP parameter editor for PQ25 BCM?
You definitely have more control now with your hardware modification but there are a lot parameters to be tweaked and definitely major improvement could be achieved compared to factory setup.

 

[Robert]

By the way, have you played with VCP parameter editor for PQ25 BCM?
You definitely have more control now with your hardware modification but there are a lot parameters to be tweaked and definitely major improvement could be achieved compared to factory setup.

There are only 3 SRA parameters available for headlamp washer adjustments:
- activation delay
- period of activation
- activation cycle count

 

[mmi]

There are only 3 SRA parameters available for headlamp washer adjustments:
- activation delay
- period of activation
- activation cycle count

View attachment 137273

Did you ever play with "activation delay"?

Just got curious what exactly is the "activation delay" -
a) just a delay after windscreen washer activation before headlight washer activates

or a kind of desired outcome:​

b) threshold time to keep only windscreen washer activated ("long press") before headlight washer activates - thus possibly could make short squirts onto windscreen without blasting headlights

 

[Robert]

I did play with it but as my headlamp wash system is not actually completed yet I never got a chance to observe the results of my tweaking.

 

[Tredder76]

Hi @mmi,

First off, thank you so much for posting this mod, I'm looking to do a similar mod on my T6, one that will allow the choice of deactivating my Lazer Lamps. I'm not a fan of the switch that the lamps come with, so want to go for a more OE install, just like what you have done. I have a vague understanding of the vans wiring, and have managed to get through various mods (with help) without understanding 100% what i was doing... All works though.

The lamps will be connected to the wire on one of the LED headlights.

To do your mod for my application (if I've understood right) I can install the bistable relay between the 12V relay and the new OE switch. I can hook up the button illumination with a neighbouring button. Is it as "simple" as that?

Before i go off on a shopping spree for the parts, I was hoping you could clarify the parts I'd need as I'm not 100% sure if everything you've listed is applicable to the install I want to do?

If I've understood correctly, I need:
- Switch (I'm going for the LHD heated windscreen switch - 7E0959622A WHS)
- blue Switch connector (4D0971636D)
- Bistable relay (3.93￡ 5% OFF|2x Dc 6v 9v 12v 24v Flip-flop Latch Relay Module Bistable Self-locking Switch Low Pulse Trigger Board For Arduino Smart Home Led - Relays - AliExpress)
- Relay connector (13.18￡ |10pcs/lot 6 Pin/way Car Tire Pressure Alarm Plug Connector For Volkswagen Golf Cc Jatta Skoda Fabia Audi A3 A4 4d0 971 636 - Cables, Adapters & Sockets - AliExpress)
- Wires ?

Thanks again.

 

[mmi]

I can hook up the button illumination with a neighbouring button. Is it as "simple" as that?

Yes, correct.

- Switch (I'm going for the LHD heated windscreen switch - 7E0959622A WHS)
- blue Switch connector (4D0971636D)

Well, the switch connector 4D0971636D is a pair with switch 7E0959622D.
I would guess for your switch -A mates with housing 4D0971636A. Please confirm with a VW dealer.

The switch connectors have guide notches/"rails" so they mate only with their correct counterpart. Anyways, the notches are easy to cut off to mate any switch.
Some more info here

Traction Control - ESC/ASR & HDA switch retrofit

Ah, and there could be a second issue. Which Engine do you have ? Only the new EU6 Engine supports the HDA ... If you have a EU5 Engine, than the ECU Firmware needs to be patched, to support this feature. How do you update the firmware? I have an EU5 highline.

www.t6forum.com

It seems that the switch connectors have got a new part number:

- Wires ?

I would recommend pre-crimped wires - I believe the part number is 000979009E.

- Relay connector (13.18￡ |10pcs/lot 6 Pin/way Car Tire Pressure Alarm Plug Connector For Volkswagen Golf Cc Jatta Skoda Fabia Audi A3 A4 4d0 971 636 - Cables, Adapters & Sockets - AliExpress)

Those are actually the switch connector housings???? So 4D0971636 (no guide notches/"rails") would mate any switch.

 

[Tredder76]

Well, the switch connector 4D0971636D is a pair with switch 7E0959622D.
I would guess for your switch -A mates with housing 4D0971636A. Please confirm with a VW dealer.

That sounds logical. I just copied the product code from your pic in your original post above. I'll research this to confirm.

Those are actually the switch connector housings???? So 4D0971636 (no guide notches/"rails") would mate any switch.

Of course, I see that now. Don't need those then.

Thanks for taking the time to answer me, much appreciated!

 

[n10n]

There are only 3 SRA parameters available for headlamp washer adjustments:
- activation delay
- period of activation
- activation cycle count

View attachment 137273

I hadn’t realized such a parameter editor exists…

more stuff to investigate