[RLause]

Originally Posted by green407

You replaced the battery, what is the voltage of the new battery?

What condition are the battery cables in?

If you run a booster cable from the battery to the starter solenoid does it start better?

Do you have good loadable power at the B terminal of the ignition switch?
(Loadable, is there enough power there to illuminate an old school sealed beam high beam head light)

If you have good power into the ignition switch, with the key in the start position, you need to check for good power out of the ignition switch at the S terminal, if you have good power there then you need to check for good power into the brake switch, if you have good power into the brake switch, then you need to check for good power out of the brake switch, if you have good power out of the brake switch then you need to check for good power into the PTO switch, if you have good power into the PTO switch then you need to check for good power out of the PTO switch, if you have good power out of the PTO switch, then you need to check for good power into starter solenoid.

If at any point you do not have good loadable power into any of these switch you have a bad wire, if you do not have any power out of any of these switches you have a bad switch.

Very, very good test method. I have used it for years. The lamp also works good when you have a short that keeps blowing the fuse. Use the lamp for a fuse while testing.