flakey rear wiper and speedo - but only when wet

[PatM]

Now that I've had my truck for a couple of weeks I've noticed that the rear wiper and speedometer tend to quit working when it's raining fairly hard. I had thought the rear wiper problem was simply from interior cleaning since it didn't work at first but then seemed fine (it stopped raining for a few days you see). The speedo seems to go good for a bit but once it's raining fairly hard it will stop climbing when speeding up while still dropping when slowing down. Eventually it just reads zero but doesn't go below that (internal pin maybe?).

If I stop and restart the truck the speedo works again while the wiper usually doesn't. It might wipe once when first turned on but nothing after that. Once things are dry the problems disappear.

I know about the stepper motor issues but I'm wondering if this might be something different since the steppers aren't exposed to rain and the wiper seems to go at the same time. Is there anyplace where there wiring for these might be exposed and getting shorted? Any ideas other than replacements?

 

[fishguy1123]

I have no clue if it could be related but do you have the rain sence wipers?

 

[PatM]

Yes I do but I pulled the fuse because the windshield isn't the one with the mounting ring and I just couldn't get the sensor mounted in a way that made it work well enough. I don't think the rear wiper is on the sense system though since when it's dry the wiper works every time.

I think I might have a different track to follow on the wiper though. This morning it wasn't working (lots of dew) but once I pulled it out of the holding bracket it worked fine. The motor may just be weak enough that the bracket is holding it back. The nonsensical part though, is that you'd think there'd be less friction when the wiper and bracket are wet.