James,
I have a 1999 Chevy Tahoe and the starter will engage when the vehicle is
running. I then have to turn the vehicle off, then start it again and hope
the starter will not engage. Jason, USA
The only way the starter can "engage" once the car is running is
the purple switch wire getting power. Possibly due to a faulty ignition switch
sending power to the starter.
It is possible for a short at/in the starter itself to be causing this.
I would have a test light hooked up to this "Purple Wire" going
to the starter to make sure that it is NOT getting power from the ignition
switch when it engages.
If the test light does not light up and the starter tries to act up changing
the starter would be the next step in my opinion!
Best wishes and thanks for the question.
James Morris
.
