Wiring question: Slave solenoid to Ignition coil

Trevthefox

Petty Officer 3rd Class
Joined
Sep 25, 2018
Messages
97
Hello again,

I have a wiring question for you guys, hopefully you can help me out. I have an '89 OMC King Cobra. After rebuilding the engine I was putting all the wiring back together and noticed some mystery wires that were cut by the previous owner. I always wondered what they were for so I did some digging around and traced the cut ends. I noticed the purple wire to the choke on the carb was in the wrong position. It was attached the BATT side of the coil instead of the AC terminal on the alternator. Also I found that the wire form the Ignition (I) terminal on the slave solenoid was attached at the solenoid end but clipped at the end where it's supposed to attach to the BATT side of the ignition coil (according to the manual wiring diagram).

Before I removed the engine everything seemed to work just fine. So my question is do I fix what wasn't broken? Is there a reason why the coil shouldn't be attached to the solenoid?

Let me know your thoughts.

Thanks everyone
 

alldodge

Moderator
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Mar 8, 2009
Messages
40,802
PO might have been using a Merc diagram and may have also had issue with ESA. Just guessing and its hard to say why folks do things. I would be inclined to put it back to original

OMC Engine Wiring.jpg
 

Trevthefox

Petty Officer 3rd Class
Joined
Sep 25, 2018
Messages
97
So I did some digging around on some car forums. Correct me if I'm wrong please. The "I" terminal on the solenoid is for ignition which is hot when the key is in "start" position. This cable should connect to the "+" side of the coil giving the coil full 12v during cranking. Once the engine starts and key is in "on" or "run" mode, the resistor wire leading from key to "+" side of the coil gives 7-9 volts to the coil instead of the full 12.

I guess the full 12 volts to the coil helps assist in starting the motor.

I also read that Ford ditched the the wire from "I" on solenoid to "+" on coil once the went to electronic ignition. However all points ignitions should still use the previously stated wire.

I think I'm just going to wire it up according to the manual we'll see if that changes anything
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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47,605
do you have points.....yes or no.

if you still have points, you still need to run the wire from the "I" or "R" terminal to the coil

if you dont have points, that wire is no longer needed.
 

Trevthefox

Petty Officer 3rd Class
Joined
Sep 25, 2018
Messages
97
do you have points.....yes or no.

if you still have points, you still need to run the wire from the "I" or "R" terminal to the coil

if you dont have points, that wire is no longer needed.

Yes i do. That's exactly what I'm going to do. Thanks
 
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