Is my solenoid dead? merc. 25XD 1986

[anonOmattie]

hello folks! i've got a small problem with the electric starter on my outboard engine. 1986 merc. 25XD long.

let me describe the observations i did so far:
- the electric starter will not crank when turning the key
- the choke does not work from my console
- the starter engine will run when connected directly to a power source
- the starter engine will (sometimes) crank when the engine is already running
- the choke will not work when the engine is running

my first few runs the starter worked perfectly. after a few weeks it would sometimes crank, sometimes not. after a few months it would not crank anymore. there was still a loud clicking noise, but eventually that also stopped.

at first i thought the starter was broken (as i had that problem earlier on another OB), but after cleaning the inside and the brushes, it ran no problem. now i'm thinking it is the solenoid that is causing the problem.

ill measure the voltage of the battery when trying to crank the electric starter, and when the engine is running.

could you all please share your thoughts when reading this? thanks in regard!

 

[Grub54891]

Sounding a bit like the ign switch is bad. Other than that, I'd clean all the battery connections, all the way to the start solenoid. Check the grounds also. Look under the dash, and make sure the connections are good there also. let us know what ya find.

 

[flyingscott]

Clean all your electrical connections to shiny bright. Pay close attention to the grounds.

 

[anonOmattie]

Im doupting the ignition switch is the problem... As the starter will crank when the engine is already running. But is coud be... I have cleaned all important connections from and to the solenoid, and even fully charged the battery overnight, with no result :/

I measured a voltage over the two solenoid poles, so when the solenoid closes the starter should engage. In reality this only hapens when the OB is already running. I measured the batt. Voltage at around 14v when running.

My theory is that the solenoid only closes when the OB is running and the voltage is higher. When not running, the voltage is lower then the solenoids threshold, thus it is not closing.

This will probably be the result of the age and coud be solved by a new one?

 

[Grub54891]

What is your voltage when just sitting? Ya know the battery can be tested by any parts store, if it's weak they will tell ya. Volts don't translate to amps, Amperage is what you need for a good battery.

 

[flyingscott]

I would look at the ignition switch.

 

[GA_Boater]

I would look at the ignition switch.

And the harness. Mercs are notorious for disintegrating wiring under the cowling and the harness.

A weak battery or bad grounds won't cause the starter to kick in while the motor is running. A bad harness with shorted wiring or a bad key switch can kick the starter in and stop the choke from working.

 

[flyingscott]

You won't have the disintegrating wiring that's more of a 70s merc problem. But definitely check your harness.
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[anonOmattie]

i've shot a short video of the problem: MOD EDIT - Change the title of the video.
as you can see when shorted, the starter cranks fine. when running, it cranks fine, when not running it would not move at all.

i took a look at the wiring in the ignition switch, but everything seemed alright in there. cant think why there would be the problem as is works normal when the OB is running.

the battery is fine... ran the waterpump of it all winter and it is still in good shape. it can supply power the starter fine too...

 

[anonOmattie]

https://youtu.be/DKxjWwUCY8k

 

[flyingscott]

I would stop doing that before you break the teeth off. Do you have power at the 2 small terminals on the solenoid with the key turned.

 

[anonOmattie]

I would stop doing that before you break the teeth off. Do you have power at the 2 small terminals on the solenoid with the key turned.

I will, just for the purpose if thowing the problem...

That would probably the last thing to check, only i need another person with me to to check that. Ill post my findings asap!

Btw... The voltage when just sitting is at around 12.6v

 

[flyingscott]

Are you sure that battery is good? Your voltage is low a good battery will sit around 13.5 volts

 

[anonOmattie]

well... as you can see in the video it starts the outboard just fine. is an external power source to trigger the solenoid a good idea?

 

[Grub54891]

No, find the problem and fix it,don't hide it with a redneck fix.

 

[anonOmattie]

No, find the problem and fix it,don't hide it with a redneck fix.

maybe my description was too short. what i meant was to use an external power source to trigger the solenoid, and see if it was the solenoid or not.

furthermore; I was doing some voltage readings, when i come across a BURNED FUSE. i didn't even know there was one right there! the Fuse came from the solenoid, connected to the same bolt as the positive wire from the battery. that cable probably provided power to the ignition switch. this explains why the choke and starter did not work!!!

I cant believe i overlooked this one... now lets hope replacing this fuse will solve all the previous problems!

 

[Grub54891]

I think you found the problem.