yamaha f100 voltage question

[nofrills]

I noticed while driving the boat the other day that the factory voltage guage was flashing 11.8.
I'm wondering if this is due to my battery being a bit low or is the alternator about to have a coronary.The specified output of the alternator is 12.2 so i would imagine my guage should read similar when the motor is running and then drop back to 12V when it is turned off.

Interesting that it read 11.8 both with the motor running and stopped the other day and when i checked it today with the motor off the battery read 12.

thanks scotty:-/

[Noelm]

hhmm it would seem a bit odd, to have less than 12V when the Motor is running! I guess a quick call to the Service people might set you straight.

[Hagar]

I would be checking it out more before next trip mate . I am running a Yammie four as well . The easiest way is simply check the gauge voltage with the engine stopped and then with it started . Should be a difference of at least half a volt . From memory mine outputs around 12.8 volts from the engine . The flashing may be a low volts indication . Check with a dealer .

Chris

[BM]

I don't see how 12.2V could be the specified output of the alternator.

A fully charged battery is 12.6V, so the alternator has to provide a higher voltage than that otherwise the battery will never charge fully.

If you have 11.8V whilst running then its likely your alternator has died and the gauge is simply reading battery voltage. Easy enough to check. Just check volts with engine off.

Cheers

[Spaniard_King]

Yep definate charging problem. the reason the voltyage is down when running is the the engine is using the voltage to run the engine :)

[nofrills]

yea thanks guys ill book it in today.
cheers scotty.

PS BM your correct the book reads a bit funny i think it means 12v and 20Amps.

Thanks again

[finga]

I would have thought the voltage with the motor going should be a fraction over 13V (minimum) say 13.2 to 13.8.
But who am I to argue over 'the book' :D

[PWCDad]

I have a new F80 (same motor as F100) after start the charge voltage (via Yamaha dash gauge not multimeter) is around 14.2 volts ...

It rises to around 14.8v as the battery comes up closer to charged from the start deficit.

Both my 4 stroke PWCs are about the same ... they sit around 14.4 ... and run baby AGM batteries (5kg, 18amp jobbies)



Regards
PWCDad

[Col_s]

Scotty.........easy fix......DF140 Suzi ;D ;D

PS We'll give you a couple hundred trade in.;D

[FrankFWM]

I would have thought the voltage with the motor going should be a fraction over 13V (minimum) say 13.2 to 13.8.
But who am I to argue over 'the book' :D

I agree - well over 13.8 when the batterries are close to full