starter inhibitor wiring?

Hi Guys,firstly apologies for the shoddy picture,drew it up quickly. I work with Forklifts and occasionally have to bypass for various reasons the trucks original Direction lever,this is done by using the basic diagram in the pic using 2way lever switch,what I want to do is incorporate a relay as a safety factor as an inhibitor switch. I was basically going to split the crank/exciter wire from the ignition to one side of the relay as 12v ign to pin 86,12v battery to pin 30,and pin 87 as output to the starter,and use a switch negative from the direction (2way) as in when switch sits out of direction both outputs would be negative,would this work????

OK on your diagram your ( 2 way ) switch is constant , not ground. Yes you can use a relay in this , but you have to diode isolate the two switch positions so that it doesn't back feed .