Wipers won't switch off

[treeman]

Hi all,

Has anyone come across the problem of wipers coming on of their own accord on slow setting?

I've looked in the wiki and found wipers not working, or juddering but not switching on themselves.

I've removed the earth from the stalk on the steering column when the problem has occurred and this didn't stop them so I don't think it is the stalk switch as it earths the circuit to turn them on. I have a feeling that it may be the relay and will fit a replacement to see if that works. Does anyone know if the relay from a saloon will work on a touring or are they different due to the rear wash wipe?

Thanks in advance for any replies.

[Brianmoooore]

No difference between saloon and touring wiper modules, but those for cars with intensive wash/wipe have a module with two extra pins.
The version with two extra pins can be used in place of the ordinary one with no ill effects.
Most common cause of your problem is a metallic object loose in the fusebox finding its way under the module and shorting pins together.

[treeman]

Many thanks for your help.

I'll try to lift the top half off the fusebox to see if there is anything under there. I'm keen to find a cause which means not having to replace the relay as mine does have the intensive wash operation.

All the best.

[Brianmoooore]

Not under the top half of the fusebox - on the deck under the lid, where all the fuses and relays are. The culprit is often a spare fuse that has fallen out of the lid.

[treeman]

Nothing loose in the fusebox to short the terminals unfortunately.

I went out tonight with the intention of checking if, when the wipers turn themselves on, a test light/meter would show that terminal 15b, F1 or F2 was shorting to earth between the fusebox and the switch causing the wipers to turn on but, typically, it behaved perfectly......I'll keep checking.

Thanks.

[Brianmoooore]

What model and age is this car, and does it have its original engine?

[treeman]

It's a 1989 325i Touring and as far as I'm aware its the original engine.

Mine is the one which was stored for 7 years which yourself and others were good enough to give good advice on when I brought it out again. Other than this and a seized heater blower (which I've free'd up) it is fine.

Oil/plusgas in the cylinders to soak for 3 weeks, turned over freely by hand. New timing belt/tensioner, all fluids renewed, oil back out of cylinders and it started first time. Did a compression test to see if all was well and got 170psi on all cylinders (a bit high according to Bently manual)

Next on the list is trace this wiper fault, check the brakes all round, fit a new rear silencer and take it for an MOT.