Washer / wiper gremlins

[SamP94]

Driving to work thismorning and i went over a speed bump. Washers and wipers came on and wont go off unless fuse is pulled or ignition is off.

The wipers will still change speed and then stop when the stalk is disconnected but the pump will still run.

Anyone ran into this issue? Have 30 mins a day to get a look on my lunch so would be good to know any common problems

Car is a 1998 940

[Ian21401]

Sounds like a fault in the switch. Somehow it has connected the washer contacts and they have stayed connected. I’m still trying to remedy a faulty switch in my 1992 940. Once the switch is removed and the plug disconnected it is possible to remove the switch cover with care and expose the innards. The switch outer case is plastic and has small cutouts which locate over projections on the switch inner. It is possible to prise outer cover away from the inner and wriggle it off. It’s not supposed to be possible but it is and care is required as there is a spring and loose bits in there which can fall out.
If you try that, best of luck.

[Laird Scooby]

What Ian said ^^^^^

[SamP94]

Thanks for the input. Ended up being a headlight wiper motor with an internal short somewhere, disconnected them and its all happy again

[Laird Scooby]

Originally Posted by SamP94

Thanks for the input. Ended up being a headlight wiper motor with an internal short somewhere, disconnected them and its all happy again

I'm glad you appear to have got it fixed but i have to say i'm not convinced.

Look at your headlamps, under where the wipers should have parked, there's a plastic covered metal stub at the bottom of each lens. The idea of these isn't just as a rest for the wiper in the park position but also so you can disable the headlamp wiper, for example when there's heavy snow or freezing conditions so you don't burn the motor out or damage the wiper blade.
You lift the wiper arm away from the headlamp lens, push it down and hook it under this stub. This prevents the wiper moving which trips an internal, thermal self-resetting fuse preventing power reaching the wiper motor.

Being self-resetting, once you release the arm from under the stub, the headlamp wipers will once again work as they should.

The problem you describe can only be a short in the switch unless your wiring is fried somewhere between the switch and the washer pumps.

Keep an eye on it, does the switch feel positive in operation or "woolly"? If it's "woolly" then there's a good chance it is the switch.

[SamP94]

Sounds reasonable. The switch feels just like a 20 year old switch, soft but present stages. Both the wipers and washers stopped as soon as i disconnected the OS headlamp wiper and started again as i plugged it back in. They havent worked since owning the car so ill leave them unplugged and see if the issue comes back.

[Ian21401]

[QUOTE=Laird Scooby;2576376]

Look at your headlamps, under where the wipers should have parked, there's a plastic covered metal stub at the bottom of each lens. The idea of these isn't just as a rest for the wiper in the park position but also so you can disable the headlamp wiper, for example when there's heavy snow or freezing conditions so you don't burn the motor out or damage the wiper blade.
You lift the wiper arm away from the headlamp lens, push it down and hook it under this stub. This prevents the wiper moving which trips an internal, thermal self-resetting fuse preventing power reaching the wiper motor.

Being self-resetting, once you release the arm from under the stub, the headlamp wipers will once again work as they should.

Dave,
Yet something else that you knew but I didn’t. You’re positively a mine of information. I thought they were simply a “bump stop” for the wiper blade and if the blade was left under them when the washers were activated the motor would try to move them with disastrous results. I knew that when refitting the wiper arms to the shaft the blade should be located under the stops but should then be moved above them once secured on the shaft. Where is that “thermal self resetting fuse” located and is there a way of knowing that it is working?

[Laird Scooby]

Originally Posted by Ian21401

Where is that “thermal self resetting fuse” located and is there a way of knowing that it is working?

Easiest way is to check the headlamp wipers are working normally, switch them off and move the arm/blade under the stop then try them again. If you get your glamorous assistant to operate the wash/wipe you should see the arms twitch a little when they first try to move then relax a few seconds later - subsequent tries (if made quickly) should cause any movement, if left a while you should see them twitch etc again.

As for the location of the thermal fuse, in/on the motor but i can't remember where exactly.

[bob12]

Should you find a 'glamorous assistant' willing to assist in these weather conditions and, rather than dropping the headlight wiper blade below the 'stop' it's just as easy to get 'G-Asst.' (with detailed tuition) to operate the wash/wipe switch and, for you to just to see if the h/light wipers are working.

Of course, if you open the window and operate the switch yourself and move fast you can get soaked by over-spray from the main windscreen wiper wash and, see the headlight wash/wipe working (or not).

Bob

[Laird Scooby]

Originally Posted by bob12

Should you find a 'glamorous assistant' willing to assist in these weather conditions and, rather than dropping the headlight wiper blade below the 'stop' it's just as easy to get 'G-Asst.' (with detailed tuition) to operate the wash/wipe switch and, for you to just to see if the h/light wipers are working.

Of course, if you open the window and operate the switch yourself and move fast you can get soaked by over-spray from the main windscreen wiper wash and, see the headlight wash/wipe working (or not).

Bob

The idea of an assistant Bob, glamorous or otherwise is to observe the minimal movement of the wiper arms when they're hooked under the stops to check the operation of the thermal fuse.