My 79 F250 460 stopped starting the other day. No click with key at all. Relay is new. I replaced the starter cable on the vehicle because if was frayed and corroded (found they had the top starter bolt in wrong, which explains the grinding on start.) But nothing changed.


Power to relay, no power at S, I or lug to starter. If I jump the two large lugs, the truck would turn sputter and die. Giving it gas did nothing, and it has gas.


The I lug was loose. upon further inspection, it was not usable. I pulled the wire out and wrapped the metal around the I terminal. Not a great connection at all, maybe not a connection.


Tried starting some more. No luck. After each attempted turn over and stop, something around the master cylinder was hissing, like letting air out. Eventually, smoke started coming in through the center and drivers side vents.


Came in to right this and realized I didn't check the S terminal for power in start. Went back out and had my son turn the key to the start position and it tried to start while testing for power at the S terminal.


With a screw driver, I held the wire to the I terminal and had him try again. It started for a bit, may have died when I released the screw driver from the I terminal wire. I got inside and tried myself and it started for a moment.

I'm at a loss as to why there seemed to be no power to the S and I terminal initially, then it returned. Again, I hadn't tested for power at S on crank originally, but the I terminal didn't spark at all as if it had a slightly loose connection.


Could the bad I terminal connection and then my poor rigging be the issue? If the I terminal isn't connected will the coil not get power?


I tested the fuse box inside with the key in the run position. Nothing had power on either side of the fuses or neatly packed aluminum foil replacements.


Wiring on this thing...right. Not worth chasing down, I plan to rewire it all.

 

The I post sends 12V+ to the coil whenever the S post is receiving power from the key. Mine will still start with the I post disconnected.

 

Find the cause of the smoke, PRONTO! Don't want to hear about yer vehicle being burnt to a crisp! When not playing with the vehicle, disconnect the negative (-) battery cable for safety until you get this squared away.

86 those "neatly packed" aluminium poor choice for a fuse.....that might be the main cause of all yer illnesses....chase that circuit and look for frayed/burnt/brittle wires.