Rear Hatch button and keyfob works sometimes?

Hi Guys,
I have a 1994 T&C with 212,000 miles..still looks and runs great.
Lately, the button on the dash and the keyfob button for opening the rear hatch only works about 30% of the time. I'm thinking that because both the keyfob and the dash button works the same,(either they do or don't together), it has to be something in the van.

Any suggestions?

thanks, Frank D.