Yamaha 150 OX66 Bad CDI?

[Bitsamonkey]

Okay, my first post was a little convoluted.

Why is my CDI not turning off the main relay when I turn off the ignition key?

 

[rodbolt]

Re: Yamaha 150 OX66 Bad CDI?

cause its not supposed to.
what problem description do you have?
post a model number so the exact system can be identified.

 

[rodbolt]

Re: Yamaha 150 OX66 Bad CDI?

actually its supposed to. but we still need a model number.
could be a bad CDI could be the relay contacts are sicking.
with the key off and the problem there test the voltage at the main relay yellow/blue wire.
when you apply 12V on the CDI yellow wire it powers up the yellow blue wire for the main relay.
could also have some corrosion issues in the harness.

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Thanks for your reply. The model number is a 1999 px150tr Vmax. I dug around the wire harness and found that the main relay is switched by the blue yellow wire which grounds it. The positive comes straight from the 30 amp fuse.
If I turn the key on the relay is turned on and everything powers up as it should.
When I turn the key off the main relay stays on and the yellow lead stays on.
If I now unplug the relay's red/blue yellow (the one from the cdi) leads everything shuts down as it should and stays off even when I plug the red/blue yellow back in. All contacts are super clean and I've gone through all of the grounds I could find. The only corrosion would have to be in the wire itself.

 

[rodbolt]

Re: Yamaha 150 OX66 Bad CDI?

like I say, the relay is powered up by the CDI from the yellow blue wire,black is the relay ground.
test the CDI harness with key off the yellow wire to the CDI should show zero volts and you should have about zero ohms between the white wire and ground.
when the white wire grounds it tell the ECU to power down.

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

It doesn't make sense that the engine starts and stops normally, but the cdi won't shut off the main relay and the yellow lead out of the cdi stays on. In any case I have an appointment with a Yamaha tech on Thursday. I imagine we might swap cdi's. I'll post results.

 

[99yam40]

Re: Yamaha 150 OX66 Bad CDI?

From what Rodbolt said, the white wire has to be grounded for it to understand that motor should shut down

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Hi, just got back from Yamaha tech. He hooked up the winky blinky and got a TPS code. Started checking leads from cdi to tps and got lots of resistance. They recommended a new engine harness to start. That's about $570 with a discount and only the beginning. I may end up parting this motor out.

 

[Asainz320]

Re: Yamaha 150 OX66 Bad CDI?

Wow! Why would you have to change the whole harness? Test what rodbolt told you. Do it yourself first before spending your money on something you probably dont even need. Just my opinion.

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Well the tech decided the harness was junk because he wasn't getting 5 volts to the TPS plug. He said he tested the leads between multi-pin plug and tps plug and found an open circuit. I went back and checked it and a bunch of other leads and they were all good. I've also got 12.5 volts to the yellow lead at the cdi with the key on and ground to the white lead with the key off.
I believe the cdi is bad and that's really depressing as they list for just under$2000!
What do I do, part the motor out on ebay or what?

 

[rodbolt]

Re: Yamaha 150 OX66 Bad CDI?

loss of 5v reference could be a CDI,a bad harness that can be repaired or another failing sensor using that same 5v circuit thats loading the circuit down.
its a simple simple system that I would carefully test long before I ordered an ECU.
the ECU generates the 5v reference.

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Thanks for your help. Do you know what other sensors could be loading down the 5 volt output? I'm not ordering anything at this point...I'll part the motor out before I shell out close to $2000 for a cdi.

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Rodbolt, you're a genius! I disconnected the atmospheric pressure sensor and presto! I've got 5V at both the tps and the aps plugs. I then plugged the tps back in and still had 5v at the aps plug. It seems the aps is the culprit.
Again this part lists for a ridiculous $186. Since I'm only boating at sea level can't I just trick the cdi by placing a resistor in line?

 

[rodbolt]

Re: Yamaha 150 OX66 Bad CDI?

as long as when your done the output voltage is 3.2 to 4.6, maybe.
never tried it.

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Okay, I put a 100k ohm resistor from the orange to the pink and get about 4.2V while running. I wonder which end of the range represents sea level? I need a winky blinky to see if I still get the TPS code.

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Holy Crap! I'd connected a universal buzzer in place of the yamaha alarm, which seemed to work fine. After Rodbolt warned about the loading of the 5V circuit I started thinking about that buzzer and the timeline of when the relay stopped shutting down. Guess what? Disconnected the buzzer and the relay starts shutting down again. Sensitive, sensitive stuff here.
Okay let's figure out how to make a winky blinky. I can get a 5V LED from radio shack, now we need a wiring diagram.

 

[99yam40]

Re: Yamaha 150 OX66 Bad CDI?

Yea, that is why they pay the engineers all that money to design the motors and there systems. It is important to replace bad parts with the proper ones. If you would have mentioned that you installed that buzzer , I am sure some one would have said it was not the right thing to do. You are lucky you did not damage something by installing parts not for these motors.
They call these water crafts, holes in the water that you throw money into, and most people must enjoy doing it cause there are a lot of those holes everywhere.
Not sure but I believe the light is not much money, buy it and use it knowing it works properly. Everyone should have the proper tools and equipment along with the necessary manuals

 

[Bitsamonkey]

Re: Yamaha 150 OX66 Bad CDI?

Just wanted to say thanks to everybody, especially Rodbolt. I've got about 60 more hours on it now and everything seems to be working fine.

Has anyone figured out how to make a winky blinky yet?

 

[rodbolt]

Re: Yamaha 150 OX66 Bad CDI?

dunno but you can buy it for about 70 dollars.
I think the mercury F115 manual has a test lamp diagram.
best tool you got sits on your neck.
if that one sucks nothig else helps.