Thanks Mike, yeah, I was afraid it would come down to checking grounds. I'm 6'4" so the idea of crawling under the dash to pull out the instrument cluster is not appealing. But, I've done more awkward things on this van. When I replaced the heater core I first removed the seat; maybe I'll do the same to make some room on the driver side. It'll probably take me a couple of weeks or so to get to it but I'll post an update on how it goes. And if anyone else has solved a similar problem, please let us know.