That's what I did to mine after the WP unit failed after 200 miles. Haven't had any problems since and I too have a slam button just in case.its not the relay that causes the intermittent failure in the starting system. its the ehc. electric harness control. just wire the relay in by bypassing the harness control so the starting system is independent from the ehc.
wire the relay outside the ehc. so it does not plug into the ehc at all.
locate the black/ red striped wire coming off the handle bar control starter button where it comes out of the harness from the right side of the handle bars into the ehc. it will be right at the top of the ehc .cut it so it no longer goes into the ehc. instead it goes to the 86 terminal on the relay from the start button.. run a ground wire for #85 terminal on the relay.. run a hot wire that comes on with the key switch to terminal 30 on the relay. number 87 at the top of the relay goes to the starter. it will be a thicker red wire that comes form the starter into the bottom of the ehc. cut it where it goes into the ehc and hook the piece that goes to the starter to the 87 terminal. now you have a start system independent of the ehc. on/off kill switch.. starter button and power on when the key is on will all work correctly.
on the relay
30 is the hot
85 is the ground
86 is power in from the button
87 is power out to starter
holding the relay so you are looking down at the terminal blades..
turn it so you are looking down at two blades horizontal at the top and 2 or 3 blades vertical across the bottom. the two horizontal blades at top - 87 is the top blade. 30 is the 2nd blade down from the top. the 2 or 3 vertical at the bottom - the far left is 86. the far right is 85. some relays have 2 some 3. if it has 3 ignore the middle one because it is not used. hopes this helps.
