tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all...

[Michael Bryson]

I have not been able to get my 2005 18HP to turn over at all with the electric start.it starts fine with the rope pull.

things I have done:

cleaned battery cables and replaced one bad connector
replaced battery and keep it charged
tested power to starter (about 13V)
replaced starter (didn't change a thing, turn the key and nothing!)
tested power at starter solenoid and when we turn the key volts go from 13 to nothing????

I'm not a electrical engineer so I could use some help trouble shooting. there seems to be good power to the starter and not sure what the solenoid not having power when key is turned means. the old starter spun a few times and then would do nothing. old starter never raised the bendix to engage the flywheel so I thought it was a bad starter. the new one does nothing. I guessed wrong? looking for help.

thank you
MB

 

[hall832]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

what is coming out of the the other side of solenoid. if its not sending the voltage to the starter you have a bad starter solenoid.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

what is coming out of the the other side of solenoid. if its not sending the voltage to the starter you have a bad starter solenoid.

how do I check if its sending voltage to the starter?

 

[pvanv]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

You guessed wrong... which is why troubleshooting is always preferable to just throwing parts at a problem. Info is in the Factory service manual (available from any dealer... many forum members... even me...). It assumes that you have basic mechanics skills.

The solenoid is an electrically-activated switch. The small green wire triggers it. The big lugs then transfer power to the starter motor. If you jumper the big lugs, you should see the starter operate. If there is good signal to trigger the solenoid, and it clicks correctly, yet the starter does not operate... and if you jumper the heavy wires and it DOES work, you have identified a solenoid problem. Then... if it still does not work... if you apply 12v directly to the starter and it does work, you have more wiring/connection issues.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

You guessed wrong... which is why troubleshooting is always preferable to just throwing parts at a problem. Info is in the Factory service manual (available from any dealer... many forum members... even me...). It assumes that you have basic mechanics skills.

The solenoid is an electrically-activated switch. The small green wire triggers it. The big lugs then transfer power to the starter motor. If you jumper the bug lugs, you should see the starter operate. If there is good signal to trigger the solenoid, and it clicks correctly, yet the starter does not operate... and if you jumper the heavy wires and it DOES work, you have identified a solenoid problem. Then... if it still does not work... if you apply 12v directly to the starter and it does work, you have more wiring/connection issues.

thank you Paul. there is 13V to the solenoid. when I jump it nothing happens. when I take a big wire and run it from the positive side of the solenoid to the bottom lug (positive) on the starter nothing happens! what next? I checked the in line fuse and its fine.

 

[pvanv]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

12v to which terminals of the solenoid? Did you confirm proper ground? Did you try connecting 12v directly to the starter?

Sounds like either you don't have ground, or the 12v lead to the motor is likely bad. Check your Factory service manual for troubleshooting info.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

12v to which terminals of the solenoid? Did you confirm proper ground? Did you try connecting 12v directly to the starter?

Sounds like either you don't have ground, or the 12v lead to the motor is likely bad. Check your Factory service manual for troubleshooting info.

how do I confirm proper ground? or check if my 12V lead to motor is bad?

 

[pvanv]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

You are working above your experience and skill level, but we may be able to help. Again, I cannot stress enough the value of the wiring diagrams in the 003-21041-0 SERVICE MANUAL MFS9.9/15/18A&B, $40.00

But, think of it this way... you need a complete path for battery power to operate the starter. So, for example, if you used a pair of known-good jumper cables, and attached the black lead to the frame of the starter, as well as the red lead to the power lug of the starter... then once the cables are connected to a known-good battery, the starter motor should turn. If not, you have a bad starter motor.

The solenoid merely connects or interrupts the 12v going to the starter. The solenoid is likewise operated by a smaller-wire 12v signal.

Of course, there are additional items, such as the neutral safety switch, and stop clip, which will prevent the solenoid from triggering under inappropriate conditions.

If the motor is not properly connected to the negative ground of the battery, you don't have a complete circuit. An ohm meter can confirm whether you have a ground or not.

If this seems daunting to you, seek the assistance of someone more experienced in marine or automotive wiring, or get to your local Tohatsu/Nissan (or Evinrude or Mercury) dealer.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

thank you Paul. I think I may have a bad battery cable. awhile back I cut the end off of my positive side battery cable because it was so corroded and installed a new cable end. it seems like the starting issue happening quicky after I did this. maybe that cable is bad. I replaced the battery and it seems that its getting power except for when I turn the key to start the motor. I will continue my search. I am trying to learn how to fix all these minor issues myself. again, thank you for your help and I am ordering a service manual too

thx, Michael

 

[pvanv]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

Michael,

Sounds like you may indeed have a bad cable... could be either the 12v or the ground... or could be one inside the cowl.

Be certain to get a Factory service manual... skip the aftermarket manuals.

Once you learn the principles, and have appropriate tools (in this case, an analog -- not digital -- ohm meter), you will be able to troubleshoot the wiring and get running again with the least investment in time, headaches, and expensive parts.

Battery cabling should be at least 10 gauge (30 amp capacity). Factory cables are at least 8 gauge (40 amp capacity). The cable terminal ends need to properly attached to correctly prepped wire, and should be sealed with adhesive-lined shrink tube to reduce corrosion.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

You guessed wrong... which is why troubleshooting is always preferable to just throwing parts at a problem. Info is in the Factory service manual (available from any dealer... many forum members... even me...). It assumes that you have basic mechanics skills.

The solenoid is an electrically-activated switch. The small green wire triggers it. The big lugs then transfer power to the starter motor. If you jumper the bug lugs, you should see the starter operate. If there is good signal to trigger the solenoid, and it clicks correctly, yet the starter does not operate... and if you jumper the heavy wires and it DOES work, you have identified a solenoid problem. Then... if it still does not work... if you apply 12v directly to the starter and it does work, you have more wiring/connection issues.

Paul,

I jumped my starter directly from the battery and it works. it wont work when the solenoid is jumped but it does when I go straight from the battery. I have 12V at the solenoid as well. could it be a bad battery cable? I have 12V but when I try the electric start nothing happens????

thank you
Michael

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

Paul,

My positive side battery cable is black on the inside. I cut a few inches back to put a new end on it and its black all the way through. is this the problem?
thank you
MB

 

[TOHATSU GURU]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

Or.....You could just check that fuse.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

checked that first. it looks fine...

 

[pvanv]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

Paul,

My positive side battery cable is black on the inside. I cut a few inches back to put a new end on it and its black all the way through. is this the problem?
thank you
MB

Black is oxidation. You can't solder to it, and a crimp connection to it will be a high resistance connection; you might see 12v at the end, until you add an electrical load (such as the starter motor)... then the voltage will drop at the poor connection. That connection will probably get warm, too.

Get new cables (at least the one you know to be bad), and you will be well on your way to finishing the repair.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

Black is oxidation. You can't solder to it, and a crimp connection to it will be a high resistance connection; you might see 12v at the end, until you add an electrical load (such as the starter motor)... then the voltage will drop at the poor connection. That connection will probably get warm, too.

Get new cables (at least the one you know to be bad), and you will be well on your way to finishing the repair.

hey Paul,

im pulling my hair out here. i couldnt get a new cable this weekend so i decided to cut some cable off to see if i could find nice clean cable. i did about 6 inches back. I applied a crimp connector and put everything back together. I have 12V everywhere but when I turn the key nothing happens! NOW when I jump the solenoid whit a screw driver the starter motors turns but it still doesn't kick the bendix up into the flywheel and crank the motor! what the hell is going on? lol

 

[pvanv]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

When troubleshooting electrical systems, one method is to divide the system in half, and test there -- that gets you 1/2 way through to isolating the problem. In other words, for test points, you have:
1- battery + terminal
2- battery side of the solenoid
3- the solenoid itself
4- starter side of the solenoid
5- starter terminal
6- motor side of ground cable
7- battery - (ground) terminal

You also have the signal circuit that triggers the solenoid.
If you turn the key and nothing happens at all (not even a click), you could have a bad fuse or neutral safety engaged, or burned coil in the solenoid.

If you apply 12v directly to the starter and it works, you have ruled out the ground side. If it does not work, you have identified a problem in the ground side.

IIRC, you did test with 12v right to the starter, and it worked, right? If so, the problem is in the + side (somewhere between the starter and the battery), not ground.

So then, if you apply 12v to the starter side of the solenoid and it works, the problem is between the solenoid and the battery... likewise, if it doesn't work well, the problem is likely that cable between the solenoid and the starter.

Based on the fact that you got good operation when jumpering to the starter, yet sluggish operation when jumpering the solenoid, it seems that you still have high resistance somewhere in the + side... maybe another poor crimp connection.

You may have a bad battery cable terminal at the solenoid, for example. If you put good 12v to the battery side of the solenoid and it works, you still have a + battery cable issue.

At this point, you may want to see a dealer.

 

[TOHATSU GURU]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

checked that first. it looks fine...

Take the spare and put in and try it again. Sometimes the element in the fuse will separate from the side, so it isn't really blown, but the fuse can still be bad.

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

thank you Paul. that makes sense. I'm trying to figure this out on my own so I really appreciate your help. MB

 

[Michael Bryson]

Re: tohatsu MFS 18 B2 2005 4 stroke electric starting problem. wont turn over at all.

Thank you. I will give that a try. MB