2002 Grand Caravan shift indicator problem

I just had the tranny rebuilt on my '02 Grand Caravan. When I picked it up from the shop, I noticed that when I start it, the indicator on the dash shows all gear positions selected at once. When I put it into any gear, it works properly, but P & N positions show everything selected. If I shift down to L & back up, everything works ok until next time I start it. I showed it to one of the transmission shop guys, he messed around under the hood a little, but it didn't change. He said he had to order a switch for it. I thought maybe it might be something simple. Any ideas?