wipers

I have a 97 Villager. When I got in this morning and started it up, the wipers jerked as if they were trying to sweep the windshield, but they didn't completely sweep, they just jerked, and, they did this my entire ride in, and they weren't even on. When the van warmed up, I tried to use them, but, they wouldn't sweep all the way....just jumped again. We had an ice storm this weekend but I don't think this is what is causing it. Where is the relay for this (if anyone thinks this is what is causing it).

thx,
shawn