Jump wiring solenoid/starter motor on Yanmar YSE12

[eebygum]

I’m trying to get my ‘spare YSE12’ engine which has been sitting in my garage started.

I’ve got the wiring loom with the ignition key and regulator but it was not connected and frankly looks nothing like the wiring diagram (included for reference) and what was on the engine; so I’m trying simplify it by (a) bypassing the wiring loom completely and (b) disconnecting the alternator belt and …. Wiring the solenoid directly to the battery to get the starter motor going.

The black wire from the solenoid goes to +ve on 110A 12V battery
The red wire from the solenoid goes to the -ve and has an inline 10A fuse
The yellow/green wire I touch onto the -ve

Every time I connect it turns the starter motor, once or twice and then blows the fuse.

I’ve taken the starter motor off the engine in this photo (and part of the casing off) to confirm I can turn the starter motor by hand (it does).

Am I doing something wrong to keep blowing the fuse ? Does this suggest there is a short in the solenoid/starter motor or is my understanding of how to wire this up completely wrong ??? (I’m a bit of dummy when it comes to electrics)

I have a multimeter to perform any tests if need be.

Any help on how to get it wired up correctly or confirm it’s knackered, gratefully received.

 

[PaulRainbow]

Main battery cable (red) goes to the bolt on terminal of the solenoid.
Large black cable goes from the battery to one of the starter mounting bolts.
Short the above red cable to the small terminal of the solenoid.

 

[B27]

Photo is not very clear!
Is the red wire connected to the left bolt on the solenoid?
The only thing on there should be direct to the motor.

Be aware that starter solenoids can draw a lot of amps.

You may have all the heavy cables in black?
The red wire may be the alternator/dynamo output, which may be on the solenoid because it's less wire than going to the battery.

To crank the engine you need just Battery -ve to engine block/start motor body
Battery +ve to RH solenoid terminal bolt,
LH solenoid terminal bolt to motor, the integral wire that's there.

Then as Paul says short the 'control' terminal of the solenoid to the battery wire to fire the solenoid and energise the motor.

 

[rotrax]

By putting a heavy screwdriver between the two heavy terminals and shorting them with it you will get the starter turning, if it is going to! Make sur you dont let it weld itself together.

I had to do this once in dire circumstances and it worked good enough to start a tractor stuck in a Cornish lane.

 

[VicS]

The black wire from the solenoid goes to +ve on 110A 12V battery
The red wire from the solenoid goes to the -ve and has an inline 10A fuse
The yellow/green wire I touch onto the -ve

This does not sound right at all but a decent sized photo would help to see what you you are describing.

There should be a heavy wire connecting the large terminal labelled "B" in the diagram to battery positive (via the isolation switch if you are including this in your temporary wiring)

There should be a heavy wire connecting one of the starter motor mounting bolts to battery negative

(There should be another heavy wire from the unlabelled large terminal disappearing into the starter motor itself)

The engine should crank if you touch a connection from the small terminal labelled "S" on to battery positive or terminal "B" . Be careful because even this connection will carry a good few amps.

Any of these connection especially the heavy ones to battery positive and negative will carry more than 10amps
.

 

[Steve_N]

I can't really see your picture, it's too small, but with the alternator disconnected or not turning all you need is battery negative to the terminal top left (NW) on the solenoid or preferably somewhere on the engine block or bellhousing, battery positive to the terminal bottom right (SE) on the solenoid and then touch/switch positive to the Lucar connector where the white wire is connected in this picture to engage the starter.

 

[PaulRainbow]

I’m trying to get my ‘spare YSE12’ engine which has been sitting in my garage started.

I’ve got the wiring loom with the ignition key and regulator but it was not connected and frankly looks nothing like the wiring diagram (included for reference) and what was on the engine; so I’m trying simplify it by (a) bypassing the wiring loom completely and (b) disconnecting the alternator belt and …. Wiring the solenoid directly to the battery to get the starter motor going.

The black wire from the solenoid goes to +ve on 110A 12V battery
The red wire from the solenoid goes to the -ve and has an inline 10A fuse
The yellow/green wire I touch onto the -ve

Every time I connect it turns the starter motor, once or twice and then blows the fuse.

I’ve taken the starter motor off the engine in this photo (and part of the casing off) to confirm I can turn the starter motor by hand (it does).

Am I doing something wrong to keep blowing the fuse ? Does this suggest there is a short in the solenoid/starter motor or is my understanding of how to wire this up completely wrong ??? (I’m a bit of dummy when it comes to electrics)

I have a multimeter to perform any tests if need be.

Any help on how to get it wired up correctly or confirm it’s knackered, gratefully received.

Having zoomed the image and looked closer, i can see exactly what is wrong.

You connected the positive wire to the solenoid connection that goes to the motor and the negative wire to the solenoid connection that should go to the battery positive. When you energise the solenoid with the yellow/green wire you create a dead short, which will obviously blow the fuse.

That said, the red and black wires you have used are totally inadequate, these need to be thicker, like the battery cables on the boat, or possibly your car. Finally, a 10a fuse would blow anyway, the motor draws far to much current for a 10a fuse.

So, right hand bolt on terminal, where you have the black wire, needs a nice fat positive cable.
No connection to the other bolt on terminal, other than the one going into the starter motor.
A nice thick negative cable needs to go to the body of the starter, a jump lead to one of the mounting lugs would be OK.
Short the spade terminal to the fat positive terminal.

 

[eebygum]

Thanks for all the advice. I’ve beefed up the cables, reconnected as advised and changed to a 30A fuse and I can now get it to ‘click’ without blowing the fuse every time I short the Terminal, but it’s not turning over the Starter Motor so maybe that’s now the problem ?

Ie, if I keep the terminal shorted for a few seconds it doesn’t turnover.

 

[VicS]

Thanks for all the advice. I’ve beefed up the cables, reconnected as advised and changed to a 30A fuse and I can now get it to ‘click’ without blowing the fuse every time I short the Terminal, but it’s not turning over the Starter Motor so maybe that’s now the problem ?

Ie, if I keep the terminal shorted for a few seconds it doesn’t turnover.

The yellow and blue cables do not look heavy enough.

The connections do not look adequate .... how are they made to the battery posts ? Twisting the wire round the battery posts ins unlikely to be good enough.

A 30 amp fuse is no where near near large enough. Get rid of it.

The cover over the brushes and commutator appears to have been removed . What's their condition ?

When you have fitted battery cable sized cables in place of the yellow and blue and with decent connections try shorting the two large terminals on the solenoid together with a metal bar ( eg a screw driver blade)

 

[Boater Sam]

Those bits of thin wire will never carry the starter motor current. Have you seen how thick jump cables are? That is what you need to the MOTOR + to the terminal, - to the case. Then short the solenoid tag to the + on the back of the motor to get it to engage.

 

[eebygum]

Those bits of thin wire will never carry the starter motor current. Have you seen how thick jump cables are? That is what you need to the MOTOR + to the terminal, - to the case. Then short the solenoid tag to the + on the back of the motor to get it to engage.

Those were the original cables ! I replaced them with copper battery cables, unfortunately I’ve concluded that the Starter Motor is probably knackered so will be advertising the engine as non-runner for spares.

 

[Graham_Wright]

That seems a drastic conclusion!
Do as directed.
To prove the starter motor itself connect the case to negative battery. Use a jump lead connected to battery positive and tap it on the connection from the solenoid into the motor. The motor should spin althought the dog won't throw out.
If the motor spins, reinvestigate the problem.

 

[PaulRainbow]

Thanks for all the advice. I’ve beefed up the cables, reconnected as advised and changed to a 30A fuse and I can now get it to ‘click’ without blowing the fuse every time I short the Terminal, but it’s not turning over the Starter Motor so maybe that’s now the problem ?

Ie, if I keep the terminal shorted for a few seconds it doesn’t turnover.

You didn't read post #7 then:

"That said, the red and black wires you have used are totally inadequate, these need to be thicker, like the battery cables on the boat, or possibly your car."

 

[PaulRainbow]

The yellow and blue cables do not look heavy enough.

The connections do not look adequate .... how are they made to the battery posts ? Twisting the wire round the battery posts ins unlikely to be good enough.

A 30 amp fuse is no where near near large enough. Get rid of it.

The cover over the brushes and commutator appears to have been removed . What's their condition ?

When you have fitted battery cable sized cables in place of the yellow and blue and with decent connections try shorting the two large terminals on the solenoid together with a metal bar ( eg a screw driver blade)

I'd agree with all of this, those wires are never going to provide enough power to turn an engine over.

 

[ithet]

Do you have a set of car jump start leads you could use (red battery +ve to solenoid, black battery -ve to starter bolt) ?