Wipers go on when car is started...

[oneighty]

I have a strange problem that has been acting up recently. When I start the car after leaving work each day the wipers will cycle 1 time. I am careful not to bump the lever so its not user error. The problem doesn't happen in the morning or evening when its cool or when I have it parked in the garage, only when its been outside in the Florida heat for a few hours. The only thing I can think of is that the heat is making some contacts come together to complete the circuit, but that doesn't explain why they only cycle once and don't keep going until things cool off.

Any ideas? Anyone have a similar problem?

[oneighty]

If I put the key to the on position even for just a second the wiper goes. If I turn the key back off it stops half way. When I put the key back to the on position it finishes that one cycle and stops. It's not actually when the started engages.

[bartlettjw]

Apparently I am digging up old posts today. My car learned this trick too, anyone else made any headway with this issue? Mine does it maybe once every 10 starts.

[walky_talky20]

I'm going to hazard a guess that it is the wiper's intermittent relay. It is probably called a wiper control module or some-such. Whatever device has the timer circuit for the intermittent operation built into it. I believe it is a relay that is under the driver's dash.

[oneighty]

I never fixed the problem. It seems to only happed when it's really hot out and the car has been in direct sunlight for a while. And even then its hit or miss. Very difficult to reproduce the problem a second time and that makes it difficult to diagnose.

[walky_talky20]

I'm sticking with the wiper module/relay on this one. Messing up when it gets hot sounds like a plausible failure. Ask the honda guys about their fuel pump relays. (They like to fail only when the car sits in the sun)

[Ben830]

Necro bump. My car started doing this. I've replaced the relay... still happening.

You guys figure switch? Or entire wiper mechanism? They're the only things left.

[4ringstg3]

Ignition starter switch?


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[walky_talky20]

I think either switch contacts or park position contacts within the wiper motor.

[Cybersombosis]

I’ve seen dust collect in these types of switches that causes the circuit to complete. Also saw smoke in steering column on my MK3 because of this. I rebuilt my switch by taking it apart, cleaning all the munged up grease and lubed it back up. Also rebuilt my high beam switch on the B5 because it was intermittent so I know these things can be taken apart.

[Ben830]

Thanks for the input boys!

New stalks aren't horribly priced either. I've already tried a new relay and that didn't fix it. A new stalk is the next cheapest option.

[walky_talky20]

This seems to be a common issue with aging B5's. Both my '01 and my brother's '00 are doing it. Mine usually when the atmosphere is more cold and wet. And it often will "chatter" or just hestitate at the park position and go around a 2nd or 3rd time before it quits.

So, I pulled the diagram to look into what might cause this:



If it's not just a wonky relay, it looks like there are 2 possibilities:

Possiblity A: 12v+ leaking through the wiper switch (stalk) onto the Low/Mist output wire, triggering the relay as if you tapped the MIST function.

Possiblity B: Ground leaking through the park contacts onto the Park output wire, triggering the relay as if the key was turned on with wipers already at mid-stroke.

Really not sure which is more likely. I'd lean toward park contacts in the motor, due to it being more "in the elements" than the switch. Looking forward to the resolution on this one.

[MetalMan]

Really not sure which is more likely. I'd lean toward park contacts in the motor, due to it being more "in the elements" than the switch. Looking forward to the resolution on this one.

Definitely a common issue, both my '01 A4 and '01 S4 had some version of this issue.
'01 A4 sometimes would take MANY wipes after being turned off, before the wipers finally stopped cycling.
'01 S4 would occasionally behave as OP shared. It wasn't super frequent though, and seemed most likely to do it in warmer weather.

Leaning toward an issue with park signal.

[B5carl]

My wipers on my 01' barely work, like it's jamming or actuators are corroded. I'm guessing because the wiper motor itself might be bad or the actuator assembly needs to be regreased. I heard it was common on many vw's but not sure why my AWM had to fail so soon. Luckily Its not my primary car.

Just a heads up Incase you have to take the assembly apart you might as well regrease. If anyone knows why this happens let me know so I can prevent it from happening again I got a used assembly off a S4 and looking to compare both when there both out of the car.