I have an 89 f150, straight 6, 4wd...My issue is when the engine gets good and hot, it won't start again unless I give it 30 min or so to cool down...It acts like a dead battery, lights and all work, but the engine won't crank...I've replaced the starter, battery, cables, solenoid...I can't figure out what is going bad when hot...

 

All the truck's details should be in your signature as this caption explains:


(phone app link)If the starter doesn't engage & spin when the key is in START, diagnose the cranking circuit. The R/LB wire at the starter relay (near the battery) should be 12V when the key is in RUN; and any time there's 12V at the relay's small terminal, it should snap loud and have 12V on both of the large terminals. Click these & read all the captions:


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(phone app link)Why? What diagnostic test did each one fail? Did each replacement pass the same test? For each replacement; what's its brand, PN, & source?

 

I changed everything out one at a time...When it wouldn't start again, I knew I had not found the problem...The starter may crank the first time, even turning the engine slowly...Then, it's dead battery syndrome...30 minutes later, bam, starts like it never had an issue...