ford tractors are listed under "new holland"
new holland trying to get to the online parts catalog is to many clicks so i use place, i bought the 555c TLB from, for a quick link...
Construction Equipment-Backhoes-Mini Excavators-Skid Steers-Pat Kelly-MO (center of page) parts catalog link direct to newhollands site. type in "ford 555" click search and pick year/model letter you have.
it costs like 150 plus bucks, but well worth getting the shop manual for the tractor. full break down of all parts in diagrams, and trouble shooting, and how to remove, test, and reinstall everything in step by step instructions.
some things to check, is make sure you have it out of gear, if you have shuttle shift make sure lever for it is in neutral, ((have had them DOH! moments)) more so when i did not realize i bumped something as i was setting down into the seat.
you might test the "starter relay" the 555c i have. all the relays were exact same model make. so i just took one out and swapped a couple times. and quickly found out i had a bad relay. ((all relays should be in the fuse box / panel. just make sure ya bring some reading glasses and damp towel and some dry towels to clean off all the dust and double check all the relays are same / make model before ya start swapping around and seeing if it will start.