I need a part number for a neutral safety switch remote control (1985 Merc 50HP ELPT)

BWR1953

Admiral
Joined
Jan 23, 2009
Messages
6,320
GA_Boater Okay, let me get some answers for ya!

The engine performed normally (electrically) on 13 Jul 20 which was the last time we were on the water. It cranked fine when started EXCEPT ONCE when I was ready to move to another spot. At that time, I thought that I'd not properly recentered the shifter. So I moved the shifter forward, then into reverse and back to center. Then the engine fired right up.

Since that time, the engine has been in the garage at home. We replaced the carb coupler assembly a few weeks ago and may have bumped something loose with the wiring during the process. Maybe. :noidea:

We've been working on the starter/ignition issue for a couple weeks. Mostly due to waiting for parts and other non-boat related stuff. But the engine HAD been cranking/running normally the last time it was used. Then suddenly didn't do anything at all when the key was turned recently. That's what started (nyuk, nyuk :p) this round of troubleshooting.

As part of our testing, we discovered the ugly Y splice. We cleaned that up and I ran a ground wire from the starter mounting bolt to the negative solenoid terminal and the upper mounting bolt for the solenoid. That's the upper part of the Y. But I left the single lead open, which is the lower leg of the Y.

Once that was done, the motor cranked normally. So we prepped it to start and it fired right up. But it wouldn't shut off. That's when I got zapped.

Over the last few days, we reconfigured the Y splice back to the way it had been before I ran the lead to the starter mounting bolt. After we reconfigured, we get nothing when the key is turned.

We continuity tested and the Y splice assembly single lead goes through the harness connector Pin 4 and all the way to the key switch, Pin M.

Thanks for telling me that the Y splice was put there by some Previous Owner. That was a real aha! moment! :encouragement:

And thanks for the reference to the mercury switch and path. I understand the circuit better now. I'll be looking closely into that area. :joyous:

We weren't able to work on the boat this morning and likely won't this evening. Maybe tomorrow I'll be able to get out there and untangle that harness to get it cleaned up and organized. Then I can trace the wire from the mercury switch to its source.



This is the way the Y splice is now. Although I don't know if it includes the mercury switch or not. I'm thinking that it's passing through the kill switch as well, since it tested continuity normally.

Y splice.jpg
 

BWR1953

Admiral
Joined
Jan 23, 2009
Messages
6,320
Six days later and we were finally able to do a little work again today. :rolleyes:

I got the wires untangled and in the process I learned a couple more things. Discovered two more ugly Y splices.

And I apparently don't have the yellow/red wires coming from the stator to the rectifier. At least, I couldn't see any. I suppose that my starting battery hasn't been charging. :facepalm:

The mercury switch has a Y which goes from the switch to the 3rd connection on the right side of the switchbox and to Pin #1 on the eight pin connector.

The other Y splice is on the red wire. It goes to the 8 pin connector, Pin 8, the positive lead of the solenoid and to the rectifier. That splice was barely covered in some worn out old cloth electrical tape.

My gut is yelling at me to "repair" those Y splices. :cool:

I didn't have time to Ohm out the mercury switch but hope to get that tested tomorrow.

Once I get it running again, I'll properly arrange the wires. Making things pretty comes last. ;)


And I have to relate this: while working on this spaghetti mess last week, the boy said "We could have been done in 15 minutes but noooo... you have to do it RIGHT!" :lol:

2.jpg


3.jpg
 

Attachments

  • 1.jpg
    1.jpg
    189.3 KB · Views: 0

BWR1953

Admiral
Joined
Jan 23, 2009
Messages
6,320
No joy again today. :mmph:

Yesterday I got all the wires out of the tangled mess they'd been in and got them, and their respective connections, cleaned up.

Today I reconnected them to their normal spots. We continuity tested from the solenoid all the way to the key switch. I tested the mercury switch. Everything was nominal. So I turned the key.

Nothing! Again! :(

I then ran a jumper from the starter motor ground to the negative side of the solenoid and bumped the key.

It cranked! Again! :yell:

A few weeks ago the engine was starting and running normally, other than needing a little carb adjustment. Now it's not even turning over when it's supposed to! I'm stumped. :noidea:

I'm getting very frustrated and discouraged here. :pout:


2.jpg
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
IF....my memory service me right......there has to be a ground wire (12 gauge) from the starter clamp to the front cover.
Check if the Starter is grounded

Make sure the Switch-pack has a good ground wire to the engine block (12 gauge min.)
 
Last edited:

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Hook up a meter between the circled solenoid stud and stud below it and check for 12 volts when the key is turned to "Start". This checks two things, that the key switch is working and the solenoid has a ground.

If no 12 volts, meter between the top stud and the mounting bolt and try the key.
  • If you have 12 volts, the solenoid has no ground.
  • To verify, check for continuity between the solenoid ground stud with the black wire and the mounting bolt.
  • If it's open, add a jumper between the mounting bolt and solenoid ground stud. The motor should crank. Leave the jumper and make it permanent.
If there is no 12 volts on stud with the yellow/red wire, the problem is the wire to the key switch or the key switch.



solenoidvolt.png
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
If the front (where the Starter solenoid is mounted on) is not properly grounded & the other ground-wires not properly connected to a good ground it still won't work

Check if the ground circuit is good on the pin of the plug & on the socket side
continuity check between Neg. battery cable & ground wires at Stater solenoid
 
Last edited:

BWR1953

Admiral
Joined
Jan 23, 2009
Messages
6,320
Hey guys, I found the problem! I had limited time today but tracked it down. Then did a quick confirmation test between rain showers.

I'll post a detailed reply tomorrow after I get everything done.

Meanwhile, I'll tease y'all with this... which is related to the actual problem! :lol:

1.jpg
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,931
Some have nuts ..some dont.
Dont see the starter ground strap in pic...
 

BWR1953

Admiral
Joined
Jan 23, 2009
Messages
6,320
Hi guys. The motor is working normally now. Thanks again for all the help! :eagerness:

I realized awhile ago that there was a grounding problem. It was just bugging me that I couldn’t find out exactly where it was and I wanted to hunt it down. :mad:

Yesterday I thought that I’d found a loose nut which had been causing my loss of ground, but that turned out to not be the case. No Almond Joy solution! :lol:

I kept troubleshooting for awhile this morning but it was very clear that the motor block is completely isolated from the front and rear mounting brackets.

So the boy and I bought some 10 gauge wire and ring connectors this afternoon, then fashioned a jumper.
1.jpg

Then we installed the jumper.
3.jpg


IF....my memory service me right......there has to be a ground wire (12 gauge) from the starter clamp to the front cover.
Check if the Starter is grounded

Make sure the Switch-pack has a good ground wire to the engine block (12 gauge min.)

I think you’re right about a ground strap of some kind having been there before. I just couldn’t find any trace of it anywhere. So we made a 10 gauge one and installed it today.

Hook up a meter between the circled solenoid stud and stud below it and check for 12 volts when the key is turned to "Start". This checks two things, that the key switch is working and the solenoid has a ground.

If no 12 volts, meter between the top stud and the mounting bolt and try the key.
  • If you have 12 volts, the solenoid has no ground.
  • To verify, check for continuity between the solenoid ground stud with the black wire and the mounting bolt.
  • If it's open, add a jumper between the mounting bolt and solenoid ground stud. The motor should crank. Leave the jumper and make it permanent.
If there is no 12 volts on stud with the yellow/red wire, the problem is the wire to the key switch or the key switch.


Thank you for all your help! :)


If the front (where the Starter solenoid is mounted on) is not properly grounded & the other ground-wires not properly connected to a good ground it still won't work

Check if the ground circuit is good on the pin of the plug & on the socket side
continuity check between Neg. battery cable & ground wires at Stater solenoid

It's all good now, thanks! :D

Tomorrow we'll do the link & sync, then tidy up the wires and put it all back together. Then maybe we can finally go fishing again! :cool:
 

Attachments

  • 2a.jpg
    2a.jpg
    532.3 KB · Views: 0
Top