Starter help please (I'm at a loss)

[Wrfkaratemonkey]

Hey everyone! I'm at a complete loss.

1999 Mercury ELPTO 40HP, very low hours.

summary: no starting issues when I parked it in the garage for the winter. Now, it only clicks when you turn the key. I have tried everything that I can think of.

to make helping me (hopefully) as easy as possible, I made a YouTube video where I show what's happening and explain everything that I have done.

https://youtu.be/lMrGAbIIgag

thanks in advance!!!

 

[Texasmark]

When you attempt to start an engine, a low power 12v (requires very low current from the battery) is applied to the starting solenoid which energizes the switch causing the high current contacts to close and put the starter across the battery leads for the high current required to start an engine. The battery can easily supply the low power signal but if it is discharged......from sitting over the winter without being recharged, or if it is time for a replacement, it can't supply the current necessary to rotate the starter.

Take your battery to a battery testing station, like an auto parts store or Walmart and have it "Load Tested". Come back on here after you have done that with the results.

 

[Wrfkaratemonkey]

I thought I mentioned it in the video but if I forgot, it's across three batteries. All of which test fine and two of which are literally brand new. And they are all charged.

 

[Texasmark]

I thought I mentioned it in the video but if I forgot, it's across three batteries. All of which test fine and two of which are literally brand new. And they are all charged.

Okaye.....Take a pair of common pliers and wearing a pair of gloves, and turning the pliers around so that the handles are protruding from your hands, short across the two copper ⅜" studs on your starting solenoid....expect a spark but push hard when you make contact and hold on for a second or two. If the starter spins the engine (if the key is in the ON position and squeeze bulb firm, engine may start) your solenoid high current contacts are pitted and can't carry the current your starter needs to spin up the engine. I think starting current on that engine will be around 150 amperes so you will need to make good contacts with the pliers.....it's an old mechanics trick in troubleshooting auto starting systems. Time for a new solenoid.

The click you hear is the solenoid energizing.....the plunger's...copper plate is electrically pulled down across the input and output ⅜" posts, completing the circuit to the starter. After that, it's up to the copper within the unit to carry the current to the starter.

 

[Wrfkaratemonkey]

Have you watched the video in the link I provided? I apologize if that sounds rude I'm just trying to save us both time. I've already done that test, and I have two brand new solenoids as well. All three behave the same and all three have passed the bench test as well.

 

[Texasmark]

Have you watched the video in the link I provided? I apologize if that sounds rude I'm just trying to save us both time. I've already done that test, and I have two brand new solenoids as well. All three behave the same and all three have passed the bench test as well.

I apologize. I will check the video and comment back if it gives me any more ideas.

Edit: I watched your video. You said you are on your 3rd solenoid, where did you get them? New? Since you shorted across the solenoid high current contacts and it "started as it should" forget everything but the solenoid circuit. The fact that we heard it clicking says that the solenoid is getting power from the control box start switch...and ground. Therefore I wouldn't worry about that other than: Put your voltmeter leads on the solenoids control pins and hit the start switch. Do you have a solid 12v, or a lower voltage? If lower you may have enough current flowing through the solenoid to cause it to close, but not enough "power" to hold the disc down on the input-output terminals and conduct adequate current.

Disconnect the 12v supply line to the input terminal of the solenoid (to get power off the circuit) and with your ohm meter ohm across the high current terminals with the solenoid closed. Zero your leads first (if you forgot). Looks like you have a HF DMM like I have and mine has about 0.4 ohms of lead resistance. On old analog meters you could zero that out but here you just have to subtract it from your measurement.

3 questions:
Origin of solenoids, control power to solenoid, contact resistance when closed. Lets go from there.

 

[Wrfkaratemonkey]

Thanks for sticking with me on this.

solenoids - one was already on the motor when this started. The second cake from Amazon. When the problem persisted I decided to spend some more money with a more solid source so the third came from Crowley Marine.

there is a solid 12V signal when they key it turned.

I'll post back in a bit with the resistance when I get home and I can check it.

 

[sam am I]

So hook your meter's neg lead to battery neg by sticking it into the lead(pb) of the battery's post (the lowest possible point in the system), while having someone hold it there, then take your meter's positive lead and........

Connect it directly to the solenoid's coil ground post and crank the motor while reading the meter. That neg wire of the solenoid's coil should stay almost 0V

Thinking you have a ground issue the way the solenoid sounded when you jumped its positive coil post to the 12V battery stud.....It's not getting enough "pull-in" current!

(or if you suspect the 12V is "dropping-out" and while still keeping you meter grounded in the lead(pb) post, measure any of where the 12V should be as you crank. If the 12V is dropping-out, your meter will go down in voltage significantly.....say down to 5V for example.

Your meter will/should be your best friend now.......There's no magic here, just an unseen issue your meter can find.

https://www.allaboutcircuits.com/tex...-construction/

 

[Texasmark]

I apologize. I will check the video and comment back if it gives me any more ideas.

Edit: I watched your video. You said you are on your 3rd solenoid, where did you get them? New? Since you shorted across the solenoid high current contacts and it "started as it should" forget everything but the solenoid circuit. The fact that we heard it clicking says that the solenoid is getting power from the control box start switch...and ground. Therefore I wouldn't worry about that other than: Put your voltmeter leads on the solenoids control pins and hit the start switch. Do you have a solid 12v, or a lower voltage? If lower you may have enough current flowing through the solenoid to cause it to close, but not enough "power" to hold the disc down on the input-output terminals and conduct adequate current.

Disconnect the 12v supply line to the input terminal of the solenoid (to get power off the circuit) and with your ohm meter ohm across the high current terminals with the solenoid closed. Zero your leads first (if you forgot). Looks like you have a HF DMM like I have and mine has about 0.4 ohms of lead resistance. On old analog meters you could zero that out but here you just have to subtract it from your measurement.

3 questions:
Origin of solenoids, control power to solenoid, contact resistance when closed. Lets go from there.

Forgot one more thing. put the meter across the solenoid power studs. Ign switch off= 12v. Ign switch to Start should be 0 volts. One would expect you'd have 12v meaning the contacts didn't close meaning the energizing coil didn't energize.

Taking Sam's comment or just walking down the wiring from input solenoid terminal with the yellow/red wire, measuring 12v, indicating that the supply side is ok, just walk down the wiring trail from the other (-) solenoid terminal...where you would expect to have some voltage (due to the failure mechanism) and follow that wire to the next terminal and measure that....if the same voltage is there, keep going. If 0 volts you just passed your bad connection....and on down the line till you get to the battery -.

 

[Wrfkaratemonkey]

Thanks guys! Sorry for the delay, busy few days with the holiday weekend. So before I got to check any of this I was at Farm and Home for something else. Long story short I decided to grab a four post tractor solenoid while I was there for the purpose of testing. I have THREE solenoids already and TWO are brand new. And yet, I figure maybe, MAYBE the two that came in just can't get it done. They pass a bench test, but I mean this problem feels so much like a solenoid I can't shake it.

so I grabbed the tractor solenoid while I was there. Today I hooked it up, turn the key, and BAM she cranks right over. Down at the lake this weekend I was talking to a guy who has basically the exact same motor, his just happens to be a 50 HP I think it was. Looks identical otherwise. He said he keeps four or five of the solenoids in the boat at any given time because his go bad a few times a year and he said it seems like every other one you order doesn't work.

the tractor solenoid just so happens to fit perfectly in the stock location on the block, so I'm good to go! I'm gonna run this solenoid instead of the factory ones. I'll grab an extra one just in case. And the two OEM ones are heading back to Amazon and Crowley as defective.

thank you guys so much for taking the time to hear me out and offer advice. I really didn't think I'd have two brand new solenoids that bench tested correctly fail to actually work. I was cursing the boat gods as loud as I could.

stay safe out there and enjoy the water!!

 

[sam am I]

Hmmmm, my Iroquois senses say Coyote thinks something in that boat is still (or was) marginal. How could they bench test (presume a 12V batt or power supply) and not the boat? On two in a row? And the original that ran for years failed in the same way? Failed in the same way the two new ones that shipped did?

And why tractor solenoids? So like John Deere? Masey? or IH? Geeesh, are these things ignition/marine enviro safe? Why not automotive? or.....I'm confused, I better nap......

Coyote also says if it smells like fish........

 

[Wrfkaratemonkey]

It's just a universal four post solenoid. I can't tell you why the others didn't work on the boat. My dads theory is that they worked ok on the bench but under the actual load on the boat they couldn't perform. Don't know, but this one is working.

 

[Texasmark]

Swag, Pull in current may have been different, or contacts larger for tractor unit...you didn't say what tractor.

Just for grins, why not take all your solenoids and measure the energizing terminal resistance. May be that the tractor is higher, requiring less current to make a solid connection, allowing for possible external resistance in the energizing circuit to matter less. Would be interesting to hear the results.

 

[Wrfkaratemonkey]

I already tossed out the original one and shipped the two replacements off to the retailers for return or I would. My assumption is that you are likely right. Since I replaced so much of the wiring during my process of elimination and the motor has so few hours and is in great shape I'm not overly concerned about the underlying reason. I have a working setup, a backup, and a trolling motor worst case to get me back to shore. It's all lakes I'm using the boat on anyway, personally I don't mess with the Mississippi.

 

[Texasmark]

I already tossed out the original one and shipped the two replacements off to the retailers for return or I would. My assumption is that you are likely right. Since I replaced so much of the wiring during my process of elimination and the motor has so few hours and is in great shape I'm not overly concerned about the underlying reason. I have a working setup, a backup, and a trolling motor worst case to get me back to shore. It's all lakes I'm using the boat on anyway, personally I don't mess with the Mississippi.

Glad you can put this behind you!