motor will not shut off with key

[Renegade1]

Hello, I am desperate and do not understand wiring - I have a 1976 Mercury 850 thunderbolt SN#4367346 , I bought this engine used and after hooking up my controls and wiring I cranked it up and it runs but will not shut off with the key. I even unplugged the wiring harness and that did not shut it off. I ended up choking it down. I have a wiring schematic and have read the forums but it is greek to me. I truly need help understanding what to do or check. please help

 

[haventaclue]

I dread to think what you have done to the engine electrics by unplugging the harness .Rectifier burned definitely,all that current hitting it and nowhere to go.
The kill system operates by grounding out the ignition switch.The salmon wire and a ground,or grounding the brown wire from the distributor to the switchbox kills the engine.Check the ignition switch,do a continuity test on the wires from the switch to plug,you are looking for a broken wire,bad ground.Clean all wires to shiny and tighten.Here's a link to your wiring diagram http://www.maxrules.com/oldmercs/Wiring/1966ona/30.gif

 

[faztbullet]

Does your have a distributer cap with 4 wire or 4 separate coil to plugs?