I have a 96' ranger with 175k and is having a problem with the o/d light flashing, when I hit about 60 mph and the battery gauge will go down when I hit the gas and will go back up when I let off the gas. This happens often and very irritating . It feels like the trucks rpm's go crazy and doesn't want to move .

 

The trans is slipping and throwing codes, at that mileage a rebuild is in your future.