I need help wiring up a key ignition.

[JonDick13926]

I have a 1976 Dolphin something (according to the title and the "dolphin" plate on the boat). The engine is a 1979 115 hp mercury (6 cyl 2 stroke carb). The throttle control (mercontrol - exactly like the one pictured) has a key ignition in it. The boat also has a key ignition that I'm assuming was for whatever engine was initially on the boat in '76. It's not wired up. The engine harness carries the wires from the throttle control to the engine and based on the wiring diagram I found most of those wires are for the key ignition and I guess a portion is for the tach (not sure how that works). The wires on the internal wiring harness are horrible. I guess they've coroded over the years and others has spliced new wires in there and they've corroded too and now I've got a horrible internal wiring harness that would cost me $160 to replace. I'm wondering if it's possible to just wire up the other key ignition instead. Here's how the independent ignition is set up:

It has six terminals on the back:

M -
M -
I - Engine Ignition??
B - Positive Battery Terminal
C - Choke
S - Starter Solonoid

The problem I'm having is, I know one of the "M"s is for the ground and one is for the kill switch. Neither is raised and they look identical so I don't know which is which and even if I did I don't know where the kill switch wire is supposed to go.

The second problem is that I don't know where the "I - Engine Ignition" wire goes.

Can someone help? I also posted a pic of the wiring diagram for my engine.

Edit to add: I forgot to mention, the reason I'm doing this is because the engine wont start. It wont do anything. The starter doesn't even click, let alone turn the flywheel. I'm 99.9% sure it's because of the now solid GREEN wires coming from the internal harness.

 

[JonDick13926]

Re: I need help wiring up a key ignition.

New dilemma!

I messed around with some stuff today and I noticed that the throttle control ignition sends power to the solenoid switch post on the solenoid when the key is turned all the way, but nothing goes to the yellow cable leading from the solenoid to the starter. So I tried the other switch (just hooking up B, M, and S) and the same thing happened. When I use a screwdriver to link the switch post on the solenoid to the post on the solenoid that goes to the starter and then turn the key again, the starter works and turns. So something must be going wrong inside of the solenoid.

Also, the starter gear turns counterclockwise and doesn't go up to engage the flywheel. When turning the starter gear manually I notice that it has to turn clockwise in order for it to move up to engage the flywheel, so then why is it that when I get the starter to actually work (by basically hot-wiring it) that it spins counterclockwise and doesn't engage the flywheel?

 

[glenn property of pam]

Re: I need help wiring up a key ignition.

sounds like you have a few problems to fix and the first is either the battery is low on charge or you have a week connection in the main cables of the starter. You need to remove the large cables one terminal at a time and polish them with sand paper until they are shinny then clean the mounting surface and put them back on. This includes where the ground is mounted to the motor. If the solenoid has only one small wire remove the solenoid and clean the base then bolt it back on, If it has 2 follow the small black and make sure that its mounted to a clean surface.
12v hates corrosion and it will make the starter drag. The starter should engage violently not slowly come up to speed. If the bendix (gear) turns clockwise to rise then the starter runs anti-clockwise but it has to get instantly up to speed before the gear gets a chance to spin at the same speed as the starter. This is what makes the bendix engage the flywheel.

link to basic ignition and what the terminals mean.
continuousWave: Whaler: Reference: Ignition Switch

 

[JonDick13926]

Re: I need help wiring up a key ignition.

sounds like you have a few problems to fix and the first is either the battery is low on charge or you have a week connection in the main cables of the starter. You need to remove the large cables one terminal at a time and polish them with sand paper until they are shinny then clean the mounting surface and put them back on. This includes where the ground is mounted to the motor. If the solenoid has only one small wire remove the solenoid and clean the base then bolt it back on, If it has 2 follow the small black and make sure that its mounted to a clean surface.
12v hates corrosion and it will make the starter drag. The starter should engage violently not slowly come up to speed. If the bendix (gear) turns clockwise to rise then the starter runs anti-clockwise but it has to get instantly up to speed before the gear gets a chance to spin at the same speed as the starter. This is what makes the bendix engage the flywheel.

link to basic ignition and what the terminals mean.
continuousWave: Whaler: Reference: Ignition Switch

Well, the battery is likely the problem considering that I'm just using my car battery to test connections. The stator needs replaced, so I didn't buy a marine battery yet because I wont even been running the engine for now. I figured while I was testing connections I'd see if the starter worked, and apparently it does but isn't getting enough juice from my car battery to engage the flywheel. However, I know the connections and main ground is good because I poked around at pretty much everything with a multimeter and got 12.55 volts where expected. I'm just not sure that the solenoid works. I'll check to make sure that the ground wire for the solenoid is grounded well tomorrow.

 

[JonDick13926]

Re: I need help wiring up a key ignition.

Update!!

Still having issues. I broke down and purchased a new internal wiring harness and replaced the old one today. The throttle control key ignition STILL doesn't work. Here's my diagnostic results:

The starter solenoid has four posts:
1. Incoming 12V directly from battery (tested and reading 12.7 volts)
2. Outgoing from solenoid to starter
3. Engine ground (tested the ground and it is indeed a good ground)
4. Start switch

When I turn the key on the throttle control while attempting to measure a voltage at the start switch on the solenoid I get 0 volts. When I wire up the other ignition switch and test for a voltage at the start switch when the key is turned I get 12.7 volts (which goes away when the key is no longer turned). However, the solenoid simply clicks and that's it. (I know the starter works, and also goes up to engage the flywheel, but only if I use a screw drive to link 12.7 volts directly to the starter.)

So what do you guys think? Bad solenoid AND bad ignition switch in the throttle control (or possible corroded wiring, in which case I'll also have to buy an external wiring harness.)

 

[glenn property of pam]

Re: I need help wiring up a key ignition.

if you turn the key and you get 12.7v across the 2 small terminals at the solenoid and the solenoid fails to click or fails to allow voltage to pass from one large terminal to the other large terminal then the solenoid is bad and needs to be replaced (check that the solenoid is wired + to + and neg to neg first).

If you turn the key and you do not get 12v to the solenoid then either the key ignition is bad (test by shorting the B wire to the S wire) or the safety switch in the controller that closes when the shifter is in neutral is bad. I hope this helps.

 

[JonDick13926]

Re: I need help wiring up a key ignition.

if you turn the key and you get 12.7v across the 2 small terminals at the solenoid and the solenoid fails to click or fails to allow voltage to pass from one large terminal to the other large terminal then the solenoid is bad and needs to be replaced (check that the solenoid is wired + to + and neg to neg first).

If you turn the key and you do not get 12v to the solenoid then either the key ignition is bad (test by shorting the B wire to the S wire) or the safety switch in the controller that closes when the shifter is in neutral is bad. I hope this helps.

This is exactly what happens, but only with the separate key ignition and not the one built into the throttle control (as that one does nothing). I ordered a sierra solenoid just now. Can't beat $20. I was expecting something more expensive.

I guess I'm going to just wire up a separate ignition. The only thing I need to figure out is where the wire for the kill switch post on the ignition switch comes from. I think I have an idea, and that's the thing on the engine that is labeled "mercury switch" and has a wire coming off of it leading through both switch boxes and all the way back to the throttle control. If that's the one, then I should be able to just wire up an independent key ignition, but it wont have neutral safety so I'll have to be careful. Right?