2012 Wiper+Wash goes on by itself

[lopat08865]

Originally Posted by CTScott

Remove the lower steering column cover (two screws that become visible when you turn the steering wheel to one side and the other, and one screw by the tilt lever), then unplug the two connectors at the base of the wiper stalk. Drive for a couple days that way and see of they come on. If they do it is the wiper motor, if they do not it is the stalk.

There are no other relays, other than the ones that are built into the stalk.

Disconnected wiper arm stalk & replaced it with a used one. No reoccurrence of problem for 2 days then it happened again today.

Thought about replacing wiper motor but decided against it because I've been persuaded that the problem lies exclusively with the washer function. Why? The wipers are SUPPOSSED to come on whenever the washer functions, so it's a washer problem, no?

So I still don't know what to do. I guess it's possible the replacement wiper stalk assembly I bought on eBay is also bad. I could buy/try another used one [or new from Toyota for $165].

Made a diagnostic appt w/Toyota for Friday at $107/hour. Really, really hoping someone here has something better to try!

[PS: Toyota parts confirmed what CTScott said: there is NO other relay for the wiper than what's in the stalk. They thought it sounded like a "Spiral Cable" a/k/a "Clock Spring", which parts out at $715 before labor ... ouch!]

[PPS: First occurrence of the problem was the morning after I drove home in the rain. FWIW, I probably turned car off without turning the wipers off. As I say, FWIW.]

[CTScott]

Originally Posted by lopat08865

Disconnected wiper arm stalk & replaced it with a used one. No reoccurrence of problem for 2 days then it happened again today.

Thought about replacing wiper motor but decided against it because I've been persuaded that the problem lies exclusively with the washer function. Why? The wipers are SUPPOSSED to come on whenever the washer functions, so it's a washer problem, no?

So I still don't know what to do. I guess it's possible the replacement wiper stalk assembly I bought on eBay is also bad. I could buy/try another used one [or new from Toyota for $165].

Made a diagnostic appt w/Toyota for Friday at $107/hour. Really, really hoping someone here has something better to try!

[PS: Toyota parts confirmed what CTScott said: there is NO other relay for the wiper than what's in the stalk. They thought it sounded like a "Spiral Cable" a/k/a "Clock Spring", which parts out at $715 before labor ... ouch!]

[PPS: First occurrence of the problem was the morning after I drove home in the rain. FWIW, I probably turned car off without turning the wipers off. As I say, FWIW.]

Gotta love wrong info from the dealer - The wiper stalk does not route through the spiral cable.

If the stalk did not fix it, then I suspect a pinched wire. The green wire to the washer motor gets grounded to make the washer run when this occurs the logic within the wiper stalk also makes the wiper run. If that green wire is damaged somewhere between the washer motor and the stalk it could be getting intermittently grounded.

[lopat08865]

Originally Posted by CTScott

Gotta love wrong info from the dealer - The wiper stalk does not route through the spiral cable.

If the stalk did not fix it, then I suspect a pinched wire. The green wire to the washer motor gets grounded to make the washer run when this occurs the logic within the wiper stalk also makes the wiper run. If that green wire is damaged somewhere between the washer motor and the stalk it could be getting intermittently grounded.

Thanks again for the quick response :-) Sounds very promising. Since it's an intermittent problem I guess there's no way to test it, I would need to track and replace the entire run of this wire?

[CTScott]

Originally Posted by lopat08865

Thanks again for the quick response :-) Sounds very promising. Since it's an intermittent problem I guess there's no way to test it, I would need to track and replace the entire run of this wire?

I would start with checking the end under the hood, that goes to the motor. You may simply find an area where it had been rubbing and the insulation is worn.

[lopat08865]

Quick search seems to show motor attached to reservoir at left front of engine compartment. So that's where I can ID the green wire to start tracing it for inspection?

[CTScott]

Originally Posted by lopat08865

Quick search seems to show motor attached to reservoir at left front of engine compartment. So that's where I can ID the green wire to start tracing it for inspection?

Correct.