What is the normal output voltage of the Yahama 8hp rectifier ?

[CM2013]

Does one know what is the normal output voltage a Yamaha charging system ?

Something is wrong with mine, I think. My battery is overcharging when I run the motor (14-15 volts). I actually noticed it when one of my instruments turned itself off as protection. It comes back on when I disconnect the alternator.

So i'm trying to find out if the charging circuit is ok. any advice/suggestions welcome.

Here's what I have done (disconnected from the battery) :

Coil resistance measured with my digital multimeter is around 1 ohm (between the two green wires ).
If I picked up the right specs from the service manual page 8-17, the supposed value for two coils is .61-.91 ohmm. So I'm almost within specs.

At the same coils , I measured 50-70 volts ac at mid rpm and 100 vac at full trottle. Service manual says 33.6 at 1500 rpm and 77 v at 3500 rpm. So I'm possibly over spec, but how can that be if the coils resistance is within specs ? I don't have the peak voltage adaptor the manual suggests to use.

Voltage at output (not connected) is 20 volt dc idle and goes around 70 volts dc at mid rpm and more at full trottle. That seems way way too high.

I connected a replacement rectifier and I get the same exact output voltage, so it's like if the installed Yamaha charger has no regulator - it's just a rectifier and in good shape. I'm puzzled.

Can someone give me some advice please or confirm voltage range at the output ? Is it possible my battery doesn't regulate the voltage from the charger correctly anymore ? the battery keeps its charge pretty good though. Am I missing something ?

This is a brand new problem since storage from last winter and after the motor got a tune up and an impellor replacement done by an authorized Yamaha service. Is it possible they accidently shorted the output and damaged something ? The disconnected wire was coiled in the handle when I brought it to the shop. The fuse is intact.

This a Yamaha 8hp F8MLHD 4 stroke 2004.

Thanks

Claude

 

[drewseigel]

Does one know what is the normal output voltage a Yamaha charging system ?

Something is wrong with mine, I think. My battery is overcharging when I run the motor (14-15 volts). I actually noticed it when one of my instruments turned itself off as protection. It comes back on when I disconnect the alternator.

So i'm trying to find out if the charging circuit is ok. any advice/suggestions welcome.

Here's what I have done (disconnected from the battery) :

Coil resistance measured with my digital multimeter is around 1 ohm (between the two green wires ).
If I picked up the right specs from the service manual page 8-17, the supposed value for two coils is .61-.91 ohmm. So I'm almost within specs.

At the same coils , I measured 50-70 volts ac at mid rpm and 100 vac at full trottle. Service manual says 33.6 at 1500 rpm and 77 v at 3500 rpm. So I'm possibly over spec, but how can that be if the coils resistance is within specs ? I don't have the peak voltage adaptor the manual suggests to use.

Voltage at output (not connected) is 20 volt dc idle and goes around 70 volts dc at mid rpm and more at full trottle. That seems way way too high.

I connected a replacement rectifier and I get the same exact output voltage, so it's like if the installed Yamaha charger has no regulator - it's just a rectifier and in good shape. I'm puzzled.

Can someone give me some advice please or confirm voltage range at the output ? Is it possible my battery doesn't regulate the voltage from the charger correctly anymore ? the battery keeps its charge pretty good though. Am I missing something ?

This is a brand new problem since storage from last winter and after the motor got a tune up and an impellor replacement done by an authorized Yamaha service. Is it possible they accidently shorted the output and damaged something ? The disconnected wire was coiled in the handle when I brought it to the shop. The fuse is intact.

This a Yamaha 8hp F8MLHD 4 stroke 2004.

Thanks

Claude

Im having the same problem. did you ever get this fixed? what was the problem / solution?

 

[99yam40]

he has not been here since he posted that back in 2013
no need to drag up old threads

 

[drewseigel]

obviously this isnt the forum for me. see ya later... im doing research, found someone with a similar problem, asked if a solution was found, and I get dissed for it?? "no need to bring up old threads"??? there is a need, I have a charging issue on my kicker!! Im in need and looking for help. if help isnt available here, I wont waste my time. youre the fleet admiral? hopefully youre not a forum moderator or anything or im sure you just push new members away like me.

 

[GA_Boater]

obviously this isnt the forum for me. see ya later... im doing research, found someone with a similar problem, asked if a solution was found, and I get dissed for it?? "no need to bring up old threads"??? there is a need, I have a charging issue on my kicker!! Im in need and looking for help. if help isnt available here, I wont waste my time. youre the fleet admiral? hopefully youre not a forum moderator or anything or im sure you just push new members away like me.

I am a Moderator. A fact was stated, which is true, and you have an issue.

It's hard for the OP to answer your question when it's been almost 7 seven years since he was here.