I have a Craftsman Lawn Mower - It runs fine but when it is shut off, it will not restart. I checked battery and its OK. I checked starter and it appears OK. But lawn mower will not restart. What could be causing the problem? On other cases when this happened, I sanded the connection son some occasions and it worked causing tractor to start. But now I can not get it to restart. I was told that it could be a problem with safety switches. Could this be problem and how could these switches be checked?

Thanks

Do you have and know how to use a multimeter?