I'm putting a 1999 150 on an older boat. I'm using a systems check wiring harness. I'm going with a new tach that has the 4 warning lights, however I want to continue to use the other old gauges on the boat. I'm worried about hooking up the warning horn. I know I will have to remove the system check plug and solder the wires, I 'm just not sure which color wires attach to the alarm horn. Where can I find a wiring diagram or can someone tell me which wires I need to splice.
