Wipers Stopping when Stationary - Is this a help or irritation ??

[StevenWilliams]

The misses first mentioned it and there is just a but more wiping action at 50. I'd say about 0.25 second difference for a complete wipe.

[Simon]

Originally Posted by StevenWilliams

Mine slows down but keeps going when the car is not moving. I like this. My old Renault Megane stopped completely and it was a pain.


Does the Rover 75 have speed sensitive wipers while the cars in motion? The reason I ask is that when on intermittent the wipers seem to speed up a little when 50 MPH is reached. I'm not sure if it's my imagination or not.

Originally Posted by JohnDotCom

Some cars have Rain Sensitive Wipers not sure about Speed Sensitive though.

I have noticed this on my car too, but as John says I have never been able to find official confirmation in any MG-Rover documentation.

[StevenWilliams]

You'd think they'd mention it in a footnote somewhere.

[Simon]

I have just discovered this in a technical document and it confirms what we have discovered:

Intermittent wipe with speed dependant function
The configurable speed dependant intermittent wipe function is controlled by the BCU which also uses K bus vehicle speed signals from the ABS ECU to control the wiper delay period. When the switch is operated to the intermittent position, the BCU measures the resistance of the rotary switch position and simultaneously monitors the vehicle speed signals from the ABS system. Using this information, the BCU adjusts the delay period according to the vehicle speed. The switch has four delay selections and the resistance, speed and delay period for each position is shown in the following table.

If a longer delay period is selected when the intermittent function is active, the longer delay will be initiated at the next wipe cycle. If a shorter delay period is selected, the wipe cycle will operate immediately after the selection is made.

If a programmed wash/wipe function is requested when intermittent is selected, the programmed wash/wipe will operate as described previously. The intermittent function will resume when the motor reaches the park position at the end of the wash/wipe cycle.

Intermittent wipe with rain sensor
The intermittent wipe function with a rain sensor fitted is controlled by the BCU and the rain sensor unit. When the switch is operated to the intermittent position, the BCU will initiate one complete wipe cycle to calibrate the rain sensor. The rain sensor continually monitors the rainfall or screen wetness over the optical area of the sensor and operates the wipers intermittently or continuously as appropriate. A photoelectric cell increases the sensitivity of the sensor in poor conditions or night driving to ensure that the screen remains clear. A heating element ensures that the optical element stays clear of ice and condensation. The heating element is controlled by the sensor which receives ambient temperature messages from the instrument pack on the K bus.

When the rain sensor is fitted, normal speed dependant and period adjustment intermittent operation is disabled and the rain sensor assumes full control of the intermittent wiper function.

[peelaaa]

Originally Posted by Simon

I have just discovered this in a technical document and it confirms what we have discovered:

The amount of detail which went into the 75 is amazing, will we ever know of every design detail in full?

Were other comparable cars designed to this high level?

[StevenWilliams]

Fantastic. I'm not going mad. And well done for finding out the details.

[Dallas]

Sorry to bring up an old topic but I do like the great information that Simon has posted up on 07/09/08 regarding the wiper functions......

I too learnt today all about the auto wipe stop function when car is in a stopped position. I thought the wipers had blown a fuse or something when they first stopped, but then they started again and I thought GREAT! an intermittent fault.

It wasn't until a mile later I realised that the wipers would stop when the vehicle stopped (lights, junction) and then I thought haaaaaaaa! I know what this is.......... but what a total wally I felt, got home and looked it up in the handbook. Yet another thing to tell the wife....

[davidbooker]

When I bought my 75 back in February 2005, I thought my wipers were faulty until I read up about it on the "Dark Side" - I don't think this club had been formed in 2005!

Anyway, I booked a T4 session, and worked out all the various options I wanted turned on and off, and I am well pleased with the result- apart from the operator infuriatingly managing to zero my 15000 mile service countdown between services, which he said was unavoidable. Didn't believe him, but I am ready to be corrected!

[Keith]

That was operator error!

Only the trip recording is zeroed during a T4 session to alter the cars options

I can't decide whether I like the auto stop option or not, at the moment I have turned it off as subconsciously I still keep switching the wipers on as I pull away or even whilst stationary sometimes

One other wiper related option I have just applied with my T4 for the summer is the option to turn off auto park and I have one of those cardboard sunshade things for the windscreen which is held in place when the car is parked by the now vertical wipers

[Keith]

Completely unrelated to wipers but another perhaps unknown function in the car is the ratchet option for the passenger seat belts, I only read that in the manual recently so not sure if it works as described but possibly great for child seats and parcels.