The MSD 2-Step is very sensitive to any voltage over 15v DC.
To use the MSD 2-Step with the JMS SparkMAX you will need to wire a automotive relay into the system. This relay will disable the SparkMAX when the MSD 2-Step is active.
Utilize a typical automotive relay wire as listed below.
85 -> GROUND
86 -> +12v wire that activates the MSD 2-Step (usually connected to a switch)
30 -> Cut the Silver GROUND Activation wire on the JMS SparkMAX…..connect one side to 30 and the other side to 87A
87A -> Cut the Silver GROUND Activation wire on the JMS SparkMAX…..connect one side to 30 and the other side to 87A
87 -> NOT CONNECTED (not used)
How it works:
Normally power is not applied to the MSD 2-Step so the JMS SparkMAX functions like normal (pin 30 is connected to pin 87A)
When staged power is applied to the MSD 2-Step, it is also applied to the SparkMAX Disable Relay……the relay energizes (pin 30 is disconnected from pin 87A) and JMS SparkMAX is disabled.
At launch power is removed from the MSD 2-Step and the SparkMAX Disable Relay…….SparkMAX works like normal.