the problem i'm having is while driving at 60mph my pt decided to shift into 3rd or limp mode. i let the car sit for about 10 to 20 minutes and things are good... for a while. then here we go again. at first the alternator was only charging at 12.66 volts and the battery was good, according to the handheld code reader and charging tester. i replaced the alternator and things seemed to be fine for 3 days. but nope again here comes the gremlin. all the wires going to trans seem to have no corrosion. now alternator is putting out 13.6volts and battery is 12.3. i need help. i want to fix this not throw parts at it.