Why won't my auto transmission operate till aboutk 1 minute after engine start? on 1999 Dodge Ram 2500

1999 Dodge RAM 2500 8.0L V10 165,500 miles.y

Cold only or every time?
Cold only. Thanks

Have fluid and filter changed!! Should take care of that.
Ok! That sounds like a good idea; I'll try it.
1 more answer , 1 more comment
I would take it to a tranny shop and have them dignose it
Thanks goodguy! That is sound advice,but I may change fluid and filters first.