Sorry, more questions. Did this problem occur before you installed a new switch? What do you mean by board? Does the engine start? Do you turn the key switch to the ON or START position when the engine starts cranking? If it starts cranking in the ON position, it will be one of two things. You either have the wrong switch (this can easily happen) or the wiring on the back of the switch is wrong. If it starts cranking in the start position, that is good, but then I assume that if you let go of the key, the starter continues to crank. If this is the case, you may have a bad solenoid. I have seen solenoids which will not disengage the energizing circuit, even though there is no power going through it, due to internal corrosion. Have you checked that both key switches are the same, both in position of the terminals and labeling of each terminal. Many inexperienced counterman, mechanics, and DIY's don't know that there are many key switches that look the same, but are wired completely different.