Hi, This is maybe more a generic question for older vehilces rather than just for the 78 e150. I get a clicking noise when I try to start the engine. I applied voltage to the s (small termminal) and the solenoid seems to click but no starter. When I put a temporary short across the two heavy amp connections, should the starter not start cranking? Instead I get a spark and a heating up screw driver. Any suggestions on the problem here. Appreciate you help. Thanks in advance. A
it sounds like your starter is bad or your motor is froze up. if you put a test light from one big terminal to the other big terminal on the starter relay (solenoid) and you turn the ignition switch to the start position the light should light up if the relay is working. You could also turn on your headlights and see if they dim when you gop to start your engine. If the headlights stay on bright the current isn't going through the starter. If they Dim when you go to start then current is being used by the starter. But I think that because your screwdriver gets hot that there is a current draw for the starter.
With the key out of the ignition, see if you can manually turn the engine. Use a socket on the crank bolt or sometimes even a socket on the alternator 15/16" nut on the pulley. If the engine turns around when you manually turn it over it's probably a bad starter. If you can't make it turn over you may have a hydrostatic lock (happens but not all that common) or a stuck engine. More than likely, it sounds like a bad starter.