Ignition wiring!

Hello all, im really hoping I can get some help with my issue!

Motor is a 1987 Evinrude 88 SPL on a 16' neptune 160. The other day I made it back to the boat ramp when turning the key didn't do anything but turn on my gauges. I'm SOMETIMES getting power to the red 12v wire behind the key ignition. I also SOMETIMES notice my volts dropping when turning the key, but nothing is happening. In line fuses are good.

The wiring on my starter solenoid (i've tried 3 but I just ordered a new one to be safe) is as follows. Top post is getting power from battery, power from the wiring harness (fused), and a single line from the top post to the fuse panel box(?). 1st small post down has two brown wires connected. Next small post down is ground, and last post is power to starter. The flat part of the solenoid is facing my starter.

I have bypassed the neutral safety switch and still cant get it to fire. Does anyone have an ACCURATE wiring diagram for my motor? see attached pictures because I don't think it is right, but it has been working like this for over two years now. (I didn't originally wire it this way). The fuse box (?) is only getting power with the white wire attached to it from the top post of the solenoid.

Are you absolutely positive the battery and cables are good, and clean? 99% of the time, problems as you describe are due to poor connection between battery cables and battery. The other 1% might be due to a nightmare in the wiring, like yours.

Go after the cables first. Don't just look at them and wiggle them, remove them and clean shiny bright and reinstall tightly.

I've often said I'm going to buy stock in the solenoid factory. They sell tons of those things to people that don't need them.

Batteries were fully charged the night prior with my noco genius onboard charger, and ran great all day and are still showing 12.9v both batteries. The connections are clean and brand new copper fittings, heat shrinked and new terminals I put on within the last 3 weeks. Im baffled how it just randomly went out. Can a solenoid go out and intermittently work? Im also trying to figure out why I have a wire from the small post on the solenoid going to the fuse panel switch box thing in the picture above.

Agreed-----Lots of solenoids and powerpacks are sold because trouble shooting is a " lost art " I believe.

I thought I went over quite a few troubleshooting options in my original post. Also why I am here looking for further input or possible causes.

you wrote: " The other day I made it back to the boat ramp when turning the key didn't do anything but turn on my gauges. I'm SOMETIMES getting power to the red 12v wire behind the key ignition. I also SOMETIMES notice my volts dropping when turning the key, but nothing is happening. In line fuses are good."

Sometimes, eh? Man, that almost screams out there is an intermittent connection between the battery and ignition switch. The ignition switch + feed does not go through the solenoid, so that is not it. That's why I told you to check the cables. Also in the same circuit are the fuse and fuse holder and the wires. We can't examine it for loose or broken wires or loose fit of the fuse in the holder from here.

Yea I was able to determine that much as well, im just a little stumped on the wiring because I can't find my exact wiring diagram or what the connections actually are. The top post has the in line fuse wire attached to it, and the two (why two? I don't know) are connected to a small post on the solenoid. Im going to check for breaks in the line today or try to trace it down. I just wish I understood why the wires are going where they are and exactly which ones are which.

You might have to buy a factory service manual to get that copyrighted diagram.

So I went and messed with it, power is going from the starter solenoid to the fuse, but not past the fuse. The fuse has blown. (previously checked out fine). I replaced it with a different fuse and it also blew. What would cause the in line fuse to blow? I also managed to slice a nice 2" gash in my hand from the broken glass.

Using the below wiring diagram roughly

Pure and simple, fuses blow because too much current flows through it. That usually is due to a wire or component shorted to ground.

If you haven't found the cause of the fuse blowing yet............................

The small RED wire with the short 20 ampere fuse is the wire that leads to the "B" (battery) terminal of the ignition switch.

If the fuse blows in the OFF position... the wire is leading to a dead short.

If the fuse blows ONLY when the key is in the ON position... remove the wires from the "A" (accessory) terminal. If the fuse now DOES NOT blow... you at least know what direction to follow to find the short (The wires you removed from the "A" terminal).

If the fuse still blows with the wires removed from the "A" terminal when the key is turned to the START position, remove the wire from the "S" terminal. If the fuse now DOES NOT blow... either the starter solenoid is flawed, wired wrong, or the electric starter is shorted internally.

So I went today and fixed it! Turns out, I had the wiring harness to the solenoid, a brown and black wire, both to the top small post. The brown wire is actually the turn ignition power which is supposed to be lone on the small top post. I then put the black wire with the other ground going to the motor, both on the small bottom post. Replaced the fuse and boom she cranked again!! I don't know what the sudden issue caused it but that power and ground from the harness were both on the smaller top post since I got the boat (like I said I didn't wire that up). Solenoid was good, ya'll were right. Good thing I now have 3 spares now lol! Thanks for all the help guys!

Yeah... that explanation would surely cause a fuse to blow.... dead short with those wires hooked together. Glad you found it.

And hey, yeah, of course.... we know it was the other guy!