i replaced 20 amp fuse w 25 amp.Runs for a while then will not start again.help

You should be concerned. Defeating the purposes of circuit protection will yield negative results and can cause a fire, as well as damaged circuitry and components. Strongly recommend having a proper circuit test done in the areas of question to see what is going on. This will take a skilled technician with quality tools and a good electrical diagram to figure out your concern. Good luck.