When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Did you replace the original starter with a brand new starter or a used one? Or rebuilt?
I had a problem with a starter in my truck I burned the stud because of a bad connection. Ford starters are also notorious for having worn end plate bushings that allow the armature to come into contact with the fields after the starter gets warm, like being cranked over or after the engine has run for a time. After everything cools off the armature contracts clearance is gained until everything is heated up again.
If you''re using a used starter you could have the same condition. If it's a rebuilt started maybe it wasn't rebuilt properly, someone might not have replace the bushing or used an incorrect on.
Bruce Lancaster, a Ford guy over at the Barn had a saying "Clean tight electrical connections = Happy Electrons" He was right, and I've often thought of that saying over the years. 30 ohms?? That's a lot.