Voltage issues 2004 Z300 TXRC

[lockhah1]

Have been lurking around this site for quite some time. A wealth of information here. Thank you very much. I recently came across an issue with my stbd motor that have me puzzled. The Multifunction Gauge voltage display blinks occasionally. Here is what I have done so far.

Fully charged the batteries and load tested - ok
Checked voltage with ignition switch "on" position. VOM employed:
@ Battery terminals - 12.9 volts
@ Battery starter - 12.9 volts
@ Multifunction Gauge display - 12.6 volts (presume this voltage drop is ok?)

Voltage at battery terminals with motor running:
@ idle -13.9 volts
@ 1500 rpm - 13.8 volts

Voltage at Multifunction Display with motor running: (note same voltage drop)
@idle - 13.4 volts
@1500 rpm - 13.4 volts

Checked regulator output voltage WITH a DVA:
@idle - 21.24 volts
@1500 rpm - 48-50 volts

Checked lighting coil voltage with a DVA:
@ idle 32-35 volts (2o3 legs, 3rd leg NIL)
@ 1500 rpm 48-50 volts (2o3 legs, 3rd - same leg NIL)
NO shorts to ground found on all three legs.
Resistance between a-b, b-c, a-c was 0.05 to 0.06 ohms each.

Other than one of the three legs of the lighting coil indicating near zero voltage, all parameters appear to be ok. Also, I did not have the guts to test the RR and lighting coil outputs at 3500 per SM.

Is the alarm (blinking voltage value at the MF gauge) triggered by the ECM or locally at the gauge?

Other than this, motor runs and behave normally. Note sure where to go from here. Thanks in advance for your help.

[formula29]

Have you simply checked the bullet connecters that connect the gauge to the harness for corrosion? if so I think I would power the gauge straight to the battery and bypass the main wire harness and see what it looks like,

[throrope]

Because a volt meter uses next to nothing current, corroded connections will test OK, but under load will drop voltage, limit current and heat up quick. I had a corroded fuse work for 10 minutes, heat and loose contact without blowing, then cool and make contact only loose again. Drove me nuts. A marine environment is tough on wires.

[lockhah1]

Gents, great suggestions. I will check for corroded or weak connections behind the MF gauge, power the MF gauge straight from the battery. This will be fun, given close quaters and tight fit! Would you happen to know which cable color?

Incidentannly, I need to make a correction to my post. RR output voltage @1500 rpm was 21.38 volts intead of 48-50. Sorry for any confusion this may have created.

[bajakeith]

Confused !!

Do you men DVA ??

[lockhah1]

Yes I did...thanks for the clarification. Mine is made by ESI.

Also, I concluded from the earlier posts the alarm is triggered locally at the MF gauge and not by the ECM...is this correct?

I have the YDS but given the motor is functioning normally, I did d not see a need run the SF.

[bajakeith]

Esi

I just went to their site, but did not see a DVA tester.. Mines A CDI and I have TONS of their electrical tools.. Good stuff.. I have a brand new LOAD PRO that I got a yr or so ago,, just have been doing voltage drop test the old way... LOL Love my FLUKE 77 and my 88A !!

[lockhah1]

Here is a link to it Electronic Specialties Inc. Professional hand held automotive test equipment. MODEL #640 D.V.A. ADAPTOR a cheaper version of the CDI. Enjoy the Fluke, they are awsome meters $$$. Got to love that min/max function!

[bajakeith]

Lockhah1

Thanks,, My CDI DVA tester that I hardy every use is in fine shape.. Thanks for the LINK and INFO..... Deep cylcle batts and outboards are not ment for each other...Find many proplems with a mirror and looking under the flywheel !!

[boscoe99]

Yes I did...thanks for the clarification. Mine is made by ESI.

Also, I concluded from the earlier posts the alarm is triggered locally at the MF gauge and not by the ECM...is this correct?

I have the YDS but given the motor is functioning normally, I did d not see a need run the SF.

Most audible alarms are set by the ECM. The ECM grounds the warning buzzer to make it sound. Low oil quantity, over temperature, kill switch closed when starter switch is engaged and fuel in water for example. However, in some models low voltage will also set the audible alarm.

If you are talking about the voltage values flashing on a Yam multi-function device due to low or high voltage it is done within the instrument itself. The ECM is not involved in this instance.

[lockhah1]

Thanks Boscoe99. Yes, this is not an audible alarm. It is the voltage flashing within the MF gauge. This specifically answered one of my questions.

Pardon my ignorance. As you know, there are three green leads comming out of the lighting coil and connecting to the RR. I'm disconnecting those from the RR and checking voltage of each with a DVA. That is, red lead from the DVA to each of the green stator wires and the black lead from the DVA to motor ground. I'm only getting getting specified voltage from two of the three leads. The 3rd lead has practically no voltage. Am I doing it wrong?

Again, thanks very much for your reply.

P.S. I think (but not completely certain) flashing of the voltage displays occurs below 12 volts. Do you know what the set point should be?

[lockhah1]

Gents, connected the MF gauge STRAIGHT to the battery, i.e. only the batterry was connected to the gauge- nothing else (as suggested by formula29). Voltage at the gauge was 12.2 and at the battery 12.68 volts. That's 10% deviation. Therefore I think the voltage indication from the gauge is bad. Do you agree? Is there a way to calibrate the gauge. In fact, traced 12.68 volts all they way to the rubber seal plug at the gauge where all the wires enter the gauge.

BTW... Yamaha MRP catalog indicates the voltage indication at the MF gauge will start flashing at 12 volts.

Out of curiosity I checked the RR output voltage with a DVM (no DVA attached) and the reading on both pin of the blue connector was about 240 mv. But with the DVA attached I get 21v at idle. Can someone explain? I would have ecpeceted. At least 13-14 volts.

[rodbolt17]

your testing it wrong.
it is a-b b-c and c-a.
nothing about green to ground for voltage.

[lockhah1]

Thanks rodbolt. The SM specifically mentioned voltage to be taken from green- green. I don't know how I missed it. Must have read it a zillion time. All good now.

As mentioned earlier, I also measured the output voltage out of the RR with a DVA. All good there as well. However, why is it that without the DVA I get near zero voltage. Same behavior on my port motor. I'm sure there is a stupidly simple answer :-) For reference, per the SM output voltage measurement is taken by disconnecting the blue plug from the fuse block, red wires (2) to ground.