My 97 f-150 starts when cold but fails when warm. Had the battery replaced by ford tec. who assured me it was fixed. Problem persists, does not fail consistently but enough to deter me from shutting it off when away from home. Any pearls of wisdom would be greatly appreciated.

 

We need a little more information. When it won't start warm, does the starter crank at normal speed? Or does the starter have trouble cranking the engine?

 

check the battery terminals. see if theyre tight and no corrosion.

do you get at least a click from the starter?

 

The information that masseyman asked for in his post, is still needed.

Without this, I would take a swag at the cable connections on the starter are corroded and need to be replaced. Again this is a swag right now, without the additional information.

 

Thank you guys for replying. When the starter does engage it cranks normally with full power. When it fails it does nothing, no click , no slow cranking. When I turn the key it hesitates for a second before it begins to crank. The battery is new as are the connections.