Low Oil Level Alarm with Full Tank...(Boscoe chim in)

[boscoe99]

Rodbolt,

Remember your audience please. You are not talking to a mechanic or mechanic apprentice.

There are many many more that do not understand the relationship between voltage and current than those that do. Or power. Or frequency. Or that voltage is electrical difference of potential.

To many the term voltage drop means as much as pura vida.

Jason is in the Life Insurance business. If he started talking Lapse Rates, Insurable Interests, Bonus Rate Annuity and other such terms my eyes would glaze over and it would be to me as if he were speaking Hebrew. I would not understand a word.

[Jason2tpa]

no
me thinks you still do not understand the relation ship of voltage AND current.

voltage is simply electrical pressure.

current MAKES the device actually work.
use Yamaha part number pap-ercli-p0-00 inserted in the brown and blue wires at the pump bullet connectors and simply do a voltage drop test.

that will tell you witch of the CURRENT paths have excessive resitance.

it is a stupid 12v motor that the module controls a ground path.
lose the 12V supply OR the ground return path and the device simply quits working.

Me thinks you're right. Doimg the best I can with the soutces I have access to. A nice complete oil system schematic of the current/ground pathway wo definitely be helpful.

[boscoe99]

Voltage drop can, has and will whip many a mokanek man's ass.

Yamaha has to explain this over and over and over again. And then some more. It is one of those things that appears impossible to understand. Until that light goes on.

All wire has some inherent voltage drop. Usually no harm no foul if the wire is sized correctly and in good condition. The wire fails internally a bit (but not completely) and Mr. Mayhem rears his ugly head.

[pstephens46]

Prior directions from Rodbolt on voltage drop testing:

your looking for a voltage DROP not battery voltage.

at the + battery TERMINAL not cable attach one lead using the DC scale. the other lead will go to the + terminal on the starter again the stud not the cable end.
turn on the key, you should see less than .5V,turn the key to start,should still see less than .7v.

now using the same autoranging DC volt scale attach one lead to the - stud at the battery the other to a good block ground.
turn on the key, you should see less than .5 V try starting it and you should still read less than .5v.

if the + wire reads more than .7V start backing up with the lead that was on the starter battery terminal IE battery switch's and such until it reads less than .7 while loaded.

if the - cable reads more than .5V start backing down the - cable looking for junctions and splices that may have failed.

what we are doing is finding the voltage DROP acrossed a resistance.

take the ground wire and visualize the circuit, barring any terminal junctions it is a straight piece of wire from point a (battery stud) to point B the ground wire attachment at the block.
the only resistance in a perfect circuit would be the resistance of the copper,very low.

now when we operate,or try to, the circuit we are using the electrical pressure,measured in volts, to force electrons(amps) down the wire.
if all is perfect the pressure drop from a to b will be a minimal loss maybe .5V or less.
now if we have a bad spot in the cable(a resistance) we may drop 5-8 or more volts ACROSS that resistor.

loose corroded cable to terminal connections can act as a resistor as can bad cables,bad cable to cable end or any junctions between point a and b.

[/QUOTE]

Thought this was a decent description.....

[rodbolt17]

the schematic is in the service manual.
plain as day it is.

but I can make it simple.

from the engine 12V+ supply travels up the red wire to the key switch.
at key on it now travels BACK to the engine via the yellow wire.

about 6" past the 10 pin harness connector it splices and turns to the brown wire heading to the oil transfer pump.
from there it heads to the oil pump,through the oil pump and is patiently waiting for either the manual switch or the oil control module to complete the ground path so them trons can flow.

remember voltage does NOT flow.
voltage is simply a measure of electrical pressure between 2 points.

see how easy this is???
way mo simple than selling insurance.

[Jason2tpa]

the schematic is in the service manual.
plain as day it is.

but I can make it simple.

from the engine 12V+ supply travels up the red wire to the key switch.
at key on it now travels BACK to the engine via the yellow wire.

about 6" past the 10 pin harness connector it splices and turns to the brown wire heading to the oil transfer pump.
from there it heads to the oil pump,through the oil pump and is patiently waiting for either the manual switch or the oil control module to complete the ground path so them trons can flow.

remember voltage does NOT flow.
voltage is simply a measure of electrical pressure between 2 points.

see how easy this is???
way mo simple than selling insurance.

I'm sure it's difficult for you to believe this, but ya that "simple" explanation of the current path makes a heck of lot more sense than the schematic I've studied. Which by the way, I've attached the schematic I have in my service manual. When I look at it I begin to feel queasy.

But you were 100% correct. I was thinking that voltage and current were the same. I had also believed that if a wire has continuity confirmed by the multimeter, this doesn't imply that same wire has the ability to carry the full amount of applied power through the wire to the load. I believe this was what was confusing me.

If the wire has continuity, why am I not getting 12v on the other end?!? That's where my head was. But now it's become more clear to me.

Be all that as it may, I ordered a new oil harness. Should have it by weekend. I'll post the result after installation. Greatly appreciate everyone's advice.

[99yam40]

Looking at that I can see why you were having a problem.
I had problems following the brown wire too
Does not show how the tilt switch it tied into the circuit and I did not see the key switch labeled to even follow that 12 + to the yellow and brown

I would think the service manual should have something showing just the oil circuit instead of looking at that bowl of noddles

[Jason2tpa]

I would think the service manual should have something showing just the oil circuit instead of looking at that bowl of noddles

I've read numerous times in threads "your service manual should have" whatever piece of info the member was asking. I purchased my service manual online, specific to my engine year. And within this manual came all the models of my year. I did not purchase it from a yamaha dealer website, but I figured it was legit. However, Ive seen wire diagrams and other schematics posted here that are far more detailed and colored. Not sure where those came from, or if the pros have access to a service manual that differs from what the public has access to.

Either way, I'd most certainly invest in a deluxe version manual if I knew how to get my hands on one. Im glad you share my thoughts when looking at the wiring schematic. At least I know Im not alone.

[99yam40]

What is the name and number on your manual?

maybe it is an after market if covers that many motors

[boscoe99]

Yamaha service manuals provide little to no theory of operation.

Wiring diagrams in many are not complete. Sections may be missing. Some are simply down right incorrect. Red wires shown being connected to black wires for instance.

Trouble shooting tips are based on an experienced mechanic who more than likely knows what to do and won't even open the book.

Later ones (since maybe 2005) are better but still have a long way to go.

My condolences to those that have to rely on a Yamaha SM for information.

[Jason2tpa]

What is the name and number on your manual?

maybe it is an after market if covers that many motors

Service Manual: LIT-18616-01-92 (Titled 115W, 130W 1998 Service Manual)
Owners Manual: LIT-18626-02-91

Both manuals have a stamp on the last page: Yamaha Motor Co., LTD

[Jason2tpa]

Yamaha service manuals provide little to no theory of operation.

Then you'll really get a kick out of this. Attached is the entire troubleshooting section in my service manual.

[99yam40]

Did you look in the electrical section for oil system, charging,starting,ignition, etc

It should all have wiring diagrams and troubleshooting steps along with specs

[Jason2tpa]

Did you look in the electrical section for oil system, charging,starting,ignition, etc

It should all have wiring diagrams and troubleshooting steps along with specs

Sure did. In the electrical section, there is no oil pump specific wire diagram. Charging, fuel enrichment, ignition, etc, yes. The only wire diagram that mentions the current pathways of the oil injection system is the diagram i posted. And there are zero troubleshooting steps. Please let me know if you have a source that supplies detailed service manuals. But my guess is boscoe has the right opinion on service manuals:

Yamaha service manuals provide little to no theory of operation.

Wiring diagrams in many are not complete. Sections may be missing. Some are simply down right incorrect. Red wires shown being connected to black wires for instance.

Trouble shooting tips are based on an experienced mechanic who more than likely knows what to do and won't even open the book.

[Jason2tpa]

Update:

At last I get to put this mess to rest. The new oil harness was delivered today. Made the connections, turned key ON, alarm sounded and reserve tanks oil pump turned on immediately. After main tank filled I turned key off, then back ON. No alarm and 3 solid bars on the tach. Peaceful feeling.

Definitely learned plenty troubleshooting this issue, which will come in handy the next time it or a similar problem occurs.

Big thanks to everyone who offered advice, especially boscoe who took loads of time answering all my emails.