The re-man starters will usually use the same type of contacts. With the voltage test, you ideally need a voltage when the starter works properly and one when it acts up. If the voltages are different, especially if the control wire voltage is much lower when the starter does not work, this would say there is a problem in the circuit feeding that wire. If the voltage is the same when the starter works and when it doesn't, this would say that the problem is inside the starter.