Wipers/Washer Continuous Run (2005 Spyder)

[RaymondFast]

I'd guess that this has already been addressed here before, but I couldn't find it by doing a search,so here goes ...

I've had my 2005 Spyder for about 2-1/2 years. It has about 125K miles and is a well-maintained daily driver.

Some time back, my windshield washer stopped working. Assuming it was just out of fluid, I didn't worry about it (although I kept forgetting refill it). About a month ago, I started observing an intermittent problem where the wipers would keep running (in low speed) for up to 15-20 minutes after turning them off. If I set the switch to delay during that time, they would continue running in low. If I set it to high, they would run in high. After a few occurrences, it seemed to stop for a week or two. Then, the wipers began running in low speed spontaneously (although still intermittently at first). After a couple of days, they came on whenever the key was on and stayed on until the key was turned off. At that point, the washer started running spontaneously also (low and behold, it wasn't out of fluid after all!) any time the wipers were running (which was any time the key was turned on). I pulled the fuses for the wiper and washer (reinstalling the wiper fuse only when it was raining).

I bought a used wiper switch and replaced mine with it. It didn't seam to help at first. I unplugged the wiper motor and plugged it back in, and they stopped. Hmm ... surely that didn't fix it, right? Nope. After a couple of days it started again. Ignition switch on = wiper and washer on. I bought a used wiper motor and replaced mine with it. Still no fix. Still ignition switch on = wiper and washer on.

I did a continuity check on the original ignition switch per the BGB and it checked out fine. I double checked to verify no continuity to the low speed terminals with the switch on off or intermittent as well. Everything suggests the problem is not associated with the wiper switch (at least not the original one). The troubleshooting guide in the BGB only indicates a problem with the motor if it fails to run (not if it fails to stop) but there is no indication that there is anything wrong with (either) wiper motor.

I've gone through the (Toyota published) wiring schematics and can find nothing else in the system where the fault can be.

Any suggestions? Has anyone come across this problem and, if so, how was it solved?

[Carolyn]

Like you, I would have suspected the switches in the stalk, but you've ruled that out.

The fact that it went away after messing with the stalk, and then came back, points to a short in the bundle of wires at the connector, either at the stalk or at the wiper motor end. 

Worth stripping back the wrapping and spreading the wires out a bit to see if it sorts it?  Then a close inspection and some extra insulation?

Certainly seems like a wiring problem (yuk!).

Just my best guess....

[jonbill]

Possibly a sticky relay?

[RaymondFast]

... Certainly seems like a wiring problem (yuk!).

Just my best guess....

Yuk is right. I was hoping someone could say, "Oh, yeah, I've seen that. It's this easy thing you haven't thought of yet ..." But I'm starting to think I'm going to be spending next weekend tracing a wiring harness. :/

Thanks for the reply.

[RaymondFast]

Possibly a sticky relay?

I don't see a relay anywhere in that circuit. Do you know of one?

Thanks.

[jonbill]

Possibly a sticky relay?

I don't see a relay anywhere in that circuit. Do you know of one?

Thanks.

No I haven't looked at the wiring diagram for this, but I'd expect a reasonably high current device like a wiper motor to be switched via relay rather than run through the cabin controls.
And the behaviour sounds like a stuck relay to me.

[Carolyn]

Possibly a sticky relay?

I don't see a relay anywhere in that circuit. Do you know of one?

Thanks.

No I haven't looked at the wiring diagram for this, but I'd expect a reasonably high current device like a wiper motor to be switched via relay rather than run through the cabin controls.
And the behaviour sounds like a stuck relay to me.

Wouldn't use the same relay for the motor and the washer??  Sounds like current getting in where it shouldn't.  The more I look at the explantion of the problem, (unplugging the motor making it go away for a while) I'l thinking wiring close to the motor, or (possibly) inside the motor!!.

[jonbill]

Possibly a sticky relay?

I don't see a relay anywhere in that circuit. Do you know of one?

Thanks.

No I haven't looked at the wiring diagram for this, but I'd expect a reasonably high current device like a wiper motor to be switched via relay rather than run through the cabin controls.
And the behaviour sounds like a stuck relay to me.

Wouldn't use the same relay for the motor and the washer??  Sounds like current getting in where it shouldn't.  The more I look at the explantion of the problem, (unplugging the motor making it go away for a while) I'l thinking wiring close to the motor, or (possibly) inside the motor!!.

Yeah, the interaction with the washer doesn't fit my theory, but isn't consistent with a wiring fault in the motor either.
A relay tray full of water might explain both.
There's a relay compartment at both ends of the car I think - can't hurt to check them out.

[RaymondFast]

My first thought when the problem came up was to look for a relay, but I couldn't find one in the circuit diagram or listed in the BGB. The troubleshooting guide in the BGB addresses wipers that won't run, but not wipers that won't stop. There is a procedure for checking the power available to the motor, but not the motor itself. I'll take a look at the process and the diagram this evening to see if I can back into a process for checking the circuit and isolating the presence of voltage (as opposed to the absence of it).

In the mean time, any other input would be appreciated.

Thanks.

[RaymondFast]

... A relay tray full of water might explain both.

That was exactly my first thought.

... There's a relay compartment at both ends of the car I think - can't hurt to check them out.

I've checked all the boxes I've found so far and everything is clean and dry. Also, I've not found anything in print suggesting there is a wiper motor relay, however I agree that does seem unusual for a load like that. Maybe I missed something. I'll have to check again.

[Carolyn]

Possibly a sticky relay?

I don't see a relay anywhere in that circuit. Do you know of one?

Thanks.

No I haven't looked at the wiring diagram for this, but I'd expect a reasonably high current device like a wiper motor to be switched via relay rather than run through the cabin controls.
And the behaviour sounds like a stuck relay to me.

Wouldn't use the same relay for the motor and the washer??  Sounds like current getting in where it shouldn't.  The more I look at the explantion of the problem, (unplugging the motor making it go away for a while) I'l thinking wiring close to the motor, or (possibly) inside the motor!!.

Yeah, the interaction with the washer doesn't fit my theory, but isn't consistent with a wiring fault in the motor either.
A relay tray full of water might explain both.
There's a relay compartment at both ends of the car I think - can't hurt to check them out.

Disagree current could be going up a wire that connects to the washer circuit (on the -ve side.)  But yes, one could well check for water ingress.  Has the makings of a ground fault.

[shnazzle]

Not sure if I've missed it but I'm assuming you've replaced the 10a and 20a fuses in fuse box in car?

[RaymondFast]

Shnazzle, the fuses are good. I've got them pulled right now to keep the wipers and washer from running continuously when the key is on.

Thanks.

[shnazzle]

Ground point ok on front suspension tower?

[Carolyn]

Good point.

I've looked at the wiring diagram and the motor control is part of the wiper motor. 
 
A fault in there could well send the current the wrong way.

[furbern]

I think it's the self parking switch - somewhere within the motor will probably be a switch that takes a permanent live, and feeds the motor except in the parked position. When you or the relay tell the motor to move by putting power to its switched feed,the motor will start and then the even if you switch off, it'll keep going till the parking switch is off, as it's fed from either your switched feed (stalk or relay) or the park switch. There'll be some kind of reduction gear from the armature, typically a worm driving a wheel and the switch will be driven by the wheel also as that performs one revolution for a sweep of the wipers. The spontaneous coming on suggests that the switch isn't switching off, or sometimes makes contact when it shouldn't. The switch will sometimes also be changeover type so it shorts  the motor to act as a brake when it turns off. You may be able to get a new switch or somehow rescusiate the old, otherwise I fear it'll be another motor. 

[shnazzle]

I think it's the self parking switch - somewhere within the motor will probably be a switch that takes a permanent live, and feeds the motor except in the parked position. When you or the relay tell the motor to move by putting power to its switched feed,the motor will start and then the even if you switch off, it'll keep going till the parking switch is off, as it's fed from either your switched feed (stalk or relay) or the park switch. There'll be some kind of reduction gear from the armature, typically a worm driving a wheel and the switch will be driven by the wheel also as that performs one revolution for a sweep of the wipers. The spontaneous coming on suggests that the switch isn't switching off, or sometimes makes contact when it shouldn't. The switch will sometimes also be changeover type so it shorts  the motor to act as a brake when it turns off. You may be able to get a new switch or somehow rescusiate the old, otherwise I fear it'll be another motor. 

.. Well damn... Listen to the man

[RaymondFast]

I think it's the self parking switch - somewhere within the motor will probably be a switch that takes a permanent live, and feeds the motor except in the parked position. When you or the relay tell the motor to move by putting power to its switched feed,the motor will start and then the even if you switch off, it'll keep going till the parking switch is off, as it's fed from either your switched feed (stalk or relay) or the park switch. There'll be some kind of reduction gear from the armature, typically a worm driving a wheel and the switch will be driven by the wheel also as that performs one revolution for a sweep of the wipers. The spontaneous coming on suggests that the switch isn't switching off, or sometimes makes contact when it shouldn't. The switch will sometimes also be changeover type so it shorts  the motor to act as a brake when it turns off. You may be able to get a new switch or somehow rescusiate the old, otherwise I fear it'll be another motor. 

furbern, I initially thought it might be the park switch also, but would that explain the washer coming on as well? I haven't had a chance to look at the hardware or the schematic today. I have replaced the motor though (with another used one), with no change in performance. So, if it is the park switch, it would have to be bad in both motors. (Of course, that's not impossible.)

I haven't tested the switch that's in there, but I did test the one that I took out (the original one) and it checked out good. So, for now, I'm assuming the switch is not the problem.

[furbern]

Oh, well another theory exploded. I have had similar before in Minis and it's been the park switch every time, usually full of water. But yes I'm with you then, it has to be upstream of the motor.That doesn't leave much. Maybe something else has got wet allowing another unrelated circuit to trigger the wipers.

[RaymondFast]

UPDATE:

I checked the wiper motor IAW the procedure in the BGB (checking for operation under voltage using jumpers) and it checked out good. Motor runs when it's supposed to and parks when it's supposed to. There was no indication of a problem with that.

I also did a continuity check of the (replacement) switch per the BGB and it also checked out good.

I checked for open circuits, short circuits, and grounds in the harness between the switch and the motor and couldn't find anything that suggested a problem. So far, the only explanation seems to be that my car is haunted.

I haven't checked the washer pump yet. I don't see anything in the wiring diagram that would indicate that it could be the problem, but I'm to the point now where I'm reaching for straws, so I'll have a look at it.

I'm certainly open to suggestions.

[Carolyn]

I've gone back over the thread.

You unplugged the motor, when you plugged it back in, all was ok, for a short while.

I take it you unplugged again to check for shorts.

Moving the wiring seems to change matters.

It isn't in the switch and it isn't in the motor.

The motor is getting power from somewhere.

Wiring near the motor is my conclusion at this stage.

[jonbill]

Is there somewhere where power and washer & motor wires pass through sheet metal together? Or a hinge?

[RaymondFast]

I've considered the likelihood of a short somewhere and, trying to narrow down my search, I stayed up last night going over the wiring diagram for the whole system trying to find where one fault could cause all the symptoms I'm seeing. The only place that looked like it might be is in the circuit for the intermittent wiper setting - which is entirely within the wiper switch. (Unfortunately, I'm not very good at reading wiring diagrams for timing circuits, so I couldn't be sure it could even occur there, but I think so.)

While going over the diagram, I started to wonder if a fault in the washer circuit could cause the washer pump to run continuously and maybe reverse power the wiper motor. (Since the wiper operates on a cam, I wouldn't know if the motor is running forward or backward.) Again, since I'm not very good at reading the intermittent wiper circuit, I couldn't tell for sure, but it looked like it might.

I tried disconnecting the washer pump electrically to see what would happen. I replaced all the fuses and, lo and behold, the system operated normally (except for the washer). I checked the connector on the washer pump harness, fully expecting to find continuous 12vdc. To my surprise, there was no voltage. I reconnected the washer and everything works exactly as designed.

I'm not sure what to make of all that except that the fault is hiding again. I wonder how long this time.