Starter wont stop cranking

[aMeyers11]

Hi everyone, I was compression testing my 1986 mercury 35 hp and ran into an issue. The first several times I turned it over eveything worked as expected. Proabably the 4th test or so of tuning It over I turned the key to the off position and it kept on cranking. I tried the key in every position and even took it out. No use. I had to unplug the battery. I tried it again and Sam's issue. I think the starter didnt run long enough to damage it thats not my worry. I've done some reading and suspect it's just a bad solenoid. Just stumped why it worked just fine the first several times. And then started doing this. It was like 30-40 degrees F out if that helps. Thanks!

 

[wrench 3]

Most likely the contacts in the solenoid were arcing when they closed and wound up arc welding themselves together.
Now, is it cranking over as soon as you reconnect the battery?

 

[aMeyers11]

I believe it only starts cranking when the key is turned all the way to the right. And it just keeps cranking after that. I can even take the key out. Once the battery is disconnected it obviously stops but I believe that's the only solution. So basically you can connect the battery but as soon as you turn the key I dont think there is any stopping it. I only tested it twice and it happened twice In a row. I was in fear of burning up the starter. What you said about the solenoid seems to make sense. Thanks for the response!

 

[wrench 3]

If you disconnect the wire from one of the small terminals on the solenoid instead of the battery and it still keeps cranking, you know that it's the solenoid. If that makes it stop cranking then the problem is in the switch or wiring,

 

[aMeyers11]

I'll be sure to give that a try and see what happens, thanks!

 

[aMeyers11]

Alright so I ended up just going ahead and replacing the starter solenoid. I think the older one was actually fine becuase I turned it over a couple times tonight and same issue. Works fine a couple times then randomly keeps cranking with key off and out. Requires battery disconnect. So it's not the solenoid. My question is could the wiring on the solenoid be bad? Could the ignition switch be bad(by guess) or is it some other wiring issue that could be bad I did test for spark tonight and I am getting some fire and it popped a couple times but I'm too afraid of attempting to start knowing it could keep cranking. Any help would be greatly appreciated thank you!

 

[aMeyers11]

Alright so I looked in my SELOC manual and found a wiring diagram for my motor. I also took some pictures of my NEW solenoid I installed. I'm confused why I have a ground wire going from bottom left to the left solenoid plate mount when in the diagram there is only one wire connected on the bottom left to a ground not 2 like on mine. Also I'm confused as to why the diagram has a red/purple wire attached to the fuse holder but mine just goes to the top stud of the solenoid and is red. My final question would be what is the "Mercury switch"? I'm sorry this is kinda long winded. Just dont know how to solve this issue. Any help would be appreciated thank you! (Still leaning towards new ignition switch?)

 

[wrench 3]

It could be the wiring on the engine, the wiring to or in the remote control box or the ignition switch. You need to narrow it down.
When it won't stop cranking disconnect the eight pin plug going into the engine. If it stops cranking the problem is in the remote wiring or the ignition switch (but be ready to disconnect the battery if it doesn't quit). If it doesn't stop cranking, then the problem is somewhere between the eight pin and the solenoid.
If the problem is in the remote control section, you need to get the yellow wire with the red tracer so that you can easily remove it from the S terminal on the ignition switch. Then when it keeps on cranking disconnect it. If it stops, the problem is the switch. If it doesn't, the problem is in the wiring.
BTW if it starts running, you will need the eight pin plugged in to shut it down.
The wiring on your solenoid may not be exactly the same as the diagram but it sounds like it should work OK.

 

[aMeyers11]

Alright that helps so much thank you! I meant to upload some pictures but they must not of gone through. I will post them below. And I will get back to you with my results. Appreciate your help sir.

 

[aMeyers11]

Here are some photos

 

[wrench 3]

I think that in the five years that the diagram covers they made some changes to the routing.

 

[aMeyers11]

Alright that makes sense. I have a couple more pictures of my solenoid and wiring, but they dont seem to want to post for some reason. I think that wiring is fine anyways. I will try and narrow it down the way you explained when I get the chance. I will report back with my findings. Thanks again!

 

[jbaranski111]

Ignition switch

 

[The Force power]

It could be the wiring on the engine, the wiring to or in the remote control box or the ignition switch. You need to narrow it down.

If the problem is in the remote control section, you need to get the yellow wire with the red tracer so that you can easily remove it from the S terminal on the ignition switch.

as wrench 3 already said, you could also try the remote circuit with it completely disconnected from the motor side and check with a multi meter (set to ohms/diode check stetting) find what wire is the red power terminal and the wire that would connect to the starter-solenoid then check for a reading; no reading the wires are not connecting (with key turned off)

If you dont have a meter, you can check it with a jumper-wire to the red wire from the plug to energize the circuit (make sure you have a ground circuit as well) then put a test light on the wire that would go to the of the starter solenoid if the light come on; the switch is most likely faulty

 

[merc850]

By this time you have probably fried the rectifier by disconnecting the battery so check that out after you have solved the problem. Just disconnect the solenoid wire when the starter is running.

 

[aMeyers11]

Do you think I fried the rectifier even if the motor was never actually running when I disconnected the neg terminal? It didnt even have spark up until this last trial where I discovered that the solenoid wasnt the problem. So I only disconnected the neg terminal while the motor has spark 1 time. The wiring checks out with my diagram. I have a feeling It could be the ignition switch. I plan to to do the testing above to narrow it down to the controls or motor wiring. Thanks for the advice!

 

[aMeyers11]

Also does anyone know the part # or have a link for the switch in these controls? I havent had time to be sure it's the switch and take apart the controls yet but want to order asap if I find that is the issue. Thanks!

 

[The Force power]

Check how many pins is has and look on Ebay, those switches are easy to find

 

[aMeyers11]

Will take it apart and look. Thanks!

 

[aMeyers11]

So here is what I found it looks like a mess and I'm not sure what to do from here?