VXII Berlina variable intermittent wipers changing delay times

[TumTum]

My 2001 Berlina has variable intermittent wipers with the same stalk as the VE (although opposite in twist up/down functions wtf). Usually the shortest delay setting results in 50/50 dwell/wipe when stationary and continuous wipe over around 30kph. As the cuff thing is rotated down, the wipe/dwell delay returns even when the car is at speed etc. (normal behaviour). Only lately, even on the shortest delay setting, it still waits 70/30 at least even when the car is going at 100kph. Why would that have changed and the pause when stopped/continuous when moving gone? I saw a thread about a VZ with similar issues and the OP thought it was only when the headlights were on. But the VZ is a totally different BCM isn't it? And now I think of it, my VE has never done the pause/wipe when stationary but constant when over 30kph (sux cause it's a great feature).
Where to look first? I can't see how it's the stalk as the longest delay setting does increase the dwell time so it's talking to the BCM as far as I can tell...

 

[Tasmaniak]

Given that everything else that is speed sensitive is working (I'm presuming cruise control, Traction and ABS are still functioning) then that only leave three wires at the BCM that could be suspect (if thats where the fault lies.) I would be checking for continuity between the Stalk and BCM for the Grey/Red wire and the Black/White wire. Grey/Black from stalk to the BCM is dwell controll. Finally Black/Yellow coming out of the stalk should read short to ground, it too comes from the dwell control.

 

[TumTum]

Thanks for the pointers. You're right, everything else you mentioned is fine. The only thing I thought of is the question of how the setting on the stalk is 'communicated' to the BCM. If it's a variable resistor, if that is ratty or loose, maybe it' sending too weak/strong a signal and the BCM is only doing as it's told? Do we even know how this function works in tandem with a BCM? I'd have to imagine it's similar to the instrument dimmer control - again from a remote switching device into the BCM. Maybe even same as fuel gauge sender - I know that a variable voltage sent to the BCM which interprets that. Looks like we're getting into the nitty gritty eh...

As a sanity check this morning, I tried with headlights on/off - no changes so it's nothing to do with a similar issue from a VZ owner.