oldfart

This thread was started a long tine ago so I doubt you will get a reply from the original poster, however, what I would do after reading what he did and taking the age of the vehicle into mind. The connection at the transmission might have some corrosion or become loose, try unplugging and plugging it back in a few times and see if it makes any difference. You could also do a continuity test on the wires going to the transmission but that will take you a bit more time. Something else that comes to mind is check carefully under the hood for any vacuum leaks, rubber elbows tend to deteriorate over time and and fail on the inside of the bend where it's difficult to see. good luck..