Would cost about $10 to see if the ignition wireing was the problem.
You need 4 bits of wire.
2 insulated Crimp on rings
5 insulated female spade connectors
1 insulated male spade Connector
1 Fused 30 amp relay
1 6mm nut bolt and spring washer
Make 2 wires with a ring on one end and a female spade on the other.
Make 1 wire with a female spade on each end.
Make 1 wire with a male spade one end on one female on the other.
Disconnect battery
Connect the existing ignition wire to pin 85 on relay using the male spade -->female spade wire as an extention.
Connect pin 86 to ground with a female spade -->ring wire (I also mounted the relay with the 6mm nut and bolt that grounds this wire)
Connect pin 87 to where old ignition wire connected with a female spade -->female spade wire
Connect pin 30 to Battery with a spade -->ring wire & reconnect the battery
Follow this for install pics etc -->
http://www.izook.com/reviews/clicky_fix/clickyfix.htm
If that does not help its new/rebuilt starter time .... like me.
One hint though, If you pull out the starter get an opinion from an auto electrician on rebuild, cause I have been quoted $350 for a new one from supercrap and $248 from Auto Pro.
Mine is being rebuilt for about $90 next week about the same as a second hand unit of unknown condition.
The top bolt and nut sux to put back in, hope your hands are smaller than mine.