1988 Ford F150 6 cyl Two Wheel Drive Manual 100000 miles
Truck stalls without warning and starter circuit is dead, headlights work, inside warning bell works, radio will not work. This has been going on for two years and I have not been able to find the problem. It will eventually start after sitting for some length of time, sometimes days, sometimes weeks, might run for a day and might run for 6 months, cold or hot engine doesn't seem to make a difference. I have replaced ignition switch, starter relay, battery ground cable and ignition control module to not avail, any advice would be greatly appreciated.
When the truck won't crank, you will have to back check from the starter,
Main Power at starter,
Power at Solenoid whit key on crank.
Starter relay power from fusible link & power from key at crank.
Clutch switch continuity when operating.
Power to clutch switch
The fusible link powers up the ignition switch and the main feed to the starter relay. There is nothing else in the diagram as far as the starting circuit is concerned. Carefully check each component when it won't start and you should find the cause. Do not disregard faulty starter or any component replaced and check continuity of wires as there may be a broken wire that is making a partial connection and then becoming open circuit.