Hi all i have a 1993 1uzfe in a surf. I Put a new battery on it and went for a drive. after 1 hr of driving i stopped and when i went to start it, it only just cranked. I did have lights and heater on for the full time. Did a test and on battery it is 13.9v unload and 13.3v lights on and heater on. Have looked on net and could be belt slipping so can order on of them. The belt is old. Did rev it to 2000rpm and it did give 13.9v unloaded. Not sure if there is a regulator on it or built into the alternator?