Yanmar 186D broken shaft

[ajaukema]

The tractor is repainted and I have no idea which parts are original or maybe put together form other tractors.
On the inside of the dashboard there's still the lime green color.

Here are some pic's:

Just enough rebuild for a test drive earlier:



This one is last summer:



I do have the parts manual which is available on internet.
In the meantime also got a service manual, but it is incomplete.
Doesn't cover the electrical parts and some other sections.

 

[ajaukema]

Look what I found on youtub:

1976??

1976 Yanmar YM186 D .9 Litre 3-Cyl diesel 4WD Tractor (18 HP) - YouTube

 

[ajaukema]

I found the schematics for a 220 in the internet, I guess this is the most close to the wiring on the tractor.




Is this correct? :
The temp sensor is NO (normally open) and the lamp gets tested during cranking as a result of the relay which is activated as it is connected to the switch which also activates the starter solenoid.

The oil press sensor is NC (normally closed) while the key is in the ON position the lamp is tested/on because there is no oil pressure. As soon as the engine cranks or runs there is oil pressure which opens the switch (in the sensor) and turns the lamp off.

 

[winston1]

I found the schematics for a 220 in the internet, I guess this is the most close to the wiring on the tractor.

View attachment 680447


Is this correct? :
The temp sensor is NO (normally open) and the lamp gets tested during cranking as a result of the relay which is activated as it is connected to the switch which also activates the starter solenoid.

The oil press sensor is NC (normally closed) while the key is in the ON position the lamp is tested/on because there is no oil pressure. As soon as the engine cranks or runs there is oil pressure which opens the switch (in the sensor) and turns the lamp off.

The schematic I attached earlier confirms that.

Not unusual for me, I erred earlier when I said the temp light only comes on when overheated. There are models that operate that way but you are right, the lamp check on the 186 does allow that light to come on insuring it works correctly.

 

[ajaukema]

Today did some testing on the wirings, finding out which wire is connected to what, most is ok.

The oil pressure wire wasn't connected to the sensor, connected it, works fine now!
Took the wire off from the Water temp sensor and tested it to ground, lamp works!
Battery lamp is on constantly on.
Disconnected the alternator (connector has 2 wires)
VAC Measurement in the 2 wires says: ....nothing
While the engine is running of course, @different speeds.
So I took it home for further inspection.

The alternator has AC or DC on the output?

 

[California]

The alternator has AC or DC on the output?

YM186 should have the later 'pancake' alternator with the diodes over in the regulator. That regulator has a short cable with six blade connector.

I think for the earlier version alternator its internal diodes are visible on the back side.

 

[rScotty]

Today did some testing on the wirings, finding out which wire is connected to what, most is ok.

The oil pressure wire wasn't connected to the sensor, connected it, works fine now!
Took the wire off from the Water temp sensor and tested it to ground, lamp works!
Battery lamp is on constantly on.
Disconnected the alternator (connector has 2 wires)
VAC Measurement in the 2 wires says: ....nothing
While the engine is running of course, @different speeds.
So I took it home for further inspection.

The alternator has AC or DC on the output?

AC or DC on those two wires depends on if the 4 rectifier plate is internal to the alternator (old style) or external. THe first will give you DC from the alternator. The second will read AC (18 volts is common at full RPM) between alternator and rectifier and then DC after that. Check back a few months in messages here. The subject came up them as well. I remember writing quite a bit on the various alternator and regulator combinations Yanmar used in that era. And how to test and fix each of them. Winston wrote a bunch, too.
rScotty

 

[ajaukema]

OK will check the forum. Just opened the alternator, only coil, no electronics, 2 terminals.

This one:

 

[California]

OK will check the forum. Just opened the alternator, only coil, no electronics, 2 terminals.

Get out your HF multimeter and check the resistance between the two output wires. It should be near zero. If infininite, see if there is a broken/burned connection in there that you can repair. But probably the windings are the weakest part.

 

[ajaukema]

Just checked, near zero impedance. also beep.
Seems OK to me.
Maybe wiring further up on the way to the regulator, or the regulator itself.
That is for tomorrow