04 9-3 wiper washer erratic

[bschwar]

The wipers and washer usually work normally at first, but after using them a bit, they either won’t park or won’t turn off. Whenever either of those occur, simultaneously the washer will stop working at all. I tried disconnecting the rain sensor and juggling around relays, but neither helped. I tried hooking up a Tech 2 and all was normal, with the wipers anyway, but I haven’t done this while they were acting up. I’m looking at the schematic and it shows some electronics controlling the wiper and washer relays located in the underhood fuse box. I’m not seeing anything other than fuses and relays in there. Is my schematic right and, if so, where are those elections located? Is it actually part of the fuse box? What should I check next? At this point I’m thinking it’s between the CIM and whatever this other wiper control electronics is. I guess it could also be wiring or a connection but it is behaving like something electronic, the way it acts up after some amount of use. Thoughts?

[bschwar]

So this is what I'm looking at. If one looks where the fuses aren't, one can see there is definitely a circuit card under there. Now what's on that card, besides connectors, I don't know. Looking at the schematics, 342 is the fuse box. Both the wiper and washer schematics show some form of electronic switch, as part of the fuse box, that talks to the bus and controls the relays. I'm thinking fuse boxes are cheap on ebay, so it may be worth a swing.

[Digger]

The under hood electrical center has its built in own programmable brain. Best advice before reprograming or replacing any parts is disconnect the battery, pull the UHC and reseat all plugs several times and hope it fixes the problem.

[bschwar]

What I found (at least so far) is the park position switch on the motor wasn’t closing. The switch, from what I read, is supposed to close in the park position. I replaced the motor with a junkyard one and so far so good. I don’t know why that would make the wipers not park as opposed to not stop. Perhaps there is some smarts in there that realizes they aren’t stopping and makes them stop. Why this would also affect the washer I don’t know. So it seems to work so far. Fingers still crossed.

[Digger]

What I found (at least so far) is the park position switch on the motor wasn’t closing. The switch, from what I read, is supposed to close in the park position. I replaced the motor with a junkyard one and so far so good. I don’t know why that would make the wipers not park as opposed to not stop. Perhaps there is some smarts in there that realizes they aren’t stopping and makes them stop. Why this would also affect the washer I don’t know. So it seems to work so far. Fingers still crossed.

Back in the 20th century when switches in the car worked like the light switch on the wall, the park switch kept the wiper motor active until it reached the limit of downward travel. The 21st century way of parking the wipers is run through the computer which supplies power to the wiper motor until it receives signal from the park position switch.