Voltage problem?

[OgreTX]

Ok, as my post total indicates I'm a FNG. My wife's 1986 G-3 seems to be overcharging (and overheating) the battery.

I wired up a direct reading (at the battery terminals) voltmeter, and when I cruise down the street, the voltage starts charging at about 14v, then slowly climbs to 16-16.5v. When I let off the accelerator, the voltage drops back down to 12.5v, but starts climbing toward 16-17v when I re-engage the accelerator.

I had the problem, when I first bought it, and I reduced the governor to get the speed down below 20MPH, and that seemed to stop the charging at 17-18v. I also have no idea if and/or how many times it may have been modified/adjusted.

My question is: Is the voltage regulator in my electric schematic, internal to the starter/generator, or is it a separate unit? Can I just change it out (do the regulators even exist for 1986 carts?), or can it be adjusted?

Ok, maybe I have several questions ... sorry. BTW, I figured it best to post it here in the Yamaha Gas forum, but it could pertain to any gas cart I guess. Still tryng to figure out the proper protocols here. My apologies if I step on toes while I learn.

Thanks for any input on this one guys,
Ogre

[bigstik40]

Although I couldn't find a G3 wiring, I'm assuming a G2 should be similar, so, the voltage regulator in your cart should be the "older" mechanical regulator and is located in the engine compartment (not internal in generator). If you can find the green and red wires on your starter/generator and follow them, they will end up connected to your regulator. (It is a small 1" x 2" metal box.) Your regulator seems to be malfunctioning and overcharging your battery (not good !!). The output from the regulator should be 14.5 - 15.5 volts when working properly. I have read somewhere here that the older regulators are adjustable, but I don't have firsthand knowledge on how it's done. Someone who knows may be along to help. HELP !!, SOMEONE !!. - RAY

[OgreTX]

Thanks, Ray.

I located the red/green from the generator (1st pic), and traced it to under the cover behind the seat (pic 2 & 3).

It appears to be a simple contact regulator (pic 4) which gets electrical power to close the contact points, and opens them when no current is applied. The screw and capture nut (pic 5) will allow some type of adjustment, but with the simplicity, it appears that it will only allow the opening and closing voltage (current) by adjusting the spring tension. Right? Wrong?

If it does allow adjustment of the charging voltage, which way (righty tighty/lefty loosy) should I adjust? I'm sure I can tinker with it and figure it out, but rather than ruin the generator, overheat the battery, or mess up the regulator (or ALL of the above), does anybody have any input for me?

Thanks again, Ray, but as usual the further I get into electrical problems, the more questions I seem to ask.

Ogre

[bigstik40]

You're doing good so far, but sorry I don't have any experience here, so can't be of any help. I would say that before you try any adjustments, make sure the contacts are not pitted or have bumps. A light filing may improve them. Make sure you disconnect the bat. + before venturing into it. Someone may be along who knows what to do. If no-one comes, maybe start a new thread asking the specific question in the title. - Good luck - RAY

[smallblock450sl]

Originally Posted by OgreTX

Thanks, Ray.

I located the red/green from the generator (1st pic), and traced it to under the cover behind the seat (pic 2 & 3).

It appears to be a simple contact regulator (pic 4) which gets electrical power to close the contact points, and opens them when no current is applied. The screw and capture nut (pic 5) will allow some type of adjustment, but with the simplicity, it appears that it will only allow the opening and closing voltage (current) by adjusting the spring tension. Right? Wrong?

If it does allow adjustment of the charging voltage, which way (righty tighty/lefty loosy) should I adjust? I'm sure I can tinker with it and figure it out, but rather than ruin the generator, overheat the battery, or mess up the regulator (or ALL of the above), does anybody have any input for me?

Thanks again, Ray, but as usual the further I get into electrical problems, the more questions I seem to ask.

Ogre

The contact's could be pitted. To adjust the voltage regulator (as long as it is a true Hitatchi), is tighten the screw (clockwise) will increase voltage output, so you will want to turn it counter clockwise for the initiall adjustment. BUT, I have found after adjustment (even just the jam nut tightning or installing the cap) can effect the reading. Don't be afraid to take your time and several adjustments (with the cap back on) to get the desired 14.5 to 15.5 volts. Lastly, after several adjustments and can not get into spec, it could be the voltage reg is bad, but I have seen batteries that are internally damaged and "want" the high voltage also.

[OgreTX]

Thanks smallblock. Taking Ray's advice, I removed the regulator and slid some very fine emory cloth between the points and contacts, and blew out any minute debris with my compressor. There is definitely a clean gap on each side of the points (depending on whether the electromagnet has closed the circuit or it is open).

I'm going to clean it thoroughly with some "carbon tet" (or other quick flash chemical), blow dry it, and replace the regulator. I'll try loosening (CCW) the screw a half turn at a time, and run the cart to check on my adjustments. I'll just make sure I don't tighten (CW) and run the voltage up any higher.

Thanks again. I'll give it a shot tomorrow, and report my results. BTW smallblock, should I connect my voltmeter to the +/- on the regulator to check charging, or just as I did before at the battery?

Wish I had some factory technical docs to see how much of a points gap is recommended ... oh well.

Ogre

[bigstik40]

Thank you smallblock450 for sharing your knowledge with us . Like your avatar says - never too old to learn . -RAY

[OgreTX]

1st, thanks to Ray and smallblock for the assistance.

I was hoping to post something here that would help others and describe explicitly what the adjustment screw does ... so much for grandiose expectations .

I changed the pressure on the spring (screw CCW) 1/2 turn, and took it for a drive. Charging was almost non-existent. It might have gotten to 13v if I turned the meter to get a parallax view, but it was not very much.

So I screwed it back in by 1/4 turn (CW), and I got about 13.5-14v. Then I set it back to the original position (another 1/4 CW), and I got 14.5-15v. I know it was working because the voltmeter would go up to 15.5v, then drop back to 14.5v, so the circuit was opening when the voltage got too high.

About the best I can post is, "clean the contacts first and then see if that fixed it" before adjustment. I think I must have had some pitting that was fixed when I used the emery cloth on it.

It appears that the adjustment (if needed) is very small for whatever changes somebody might need.

Thanks again for the help guys.

Ogre

[smallblock450sl]

Sorry, sometimes it's hard to post all the variables Yes alot of times, cleaning and even a "very small" adjustment will fix/correct that voltage regulator. I failed to mention the "very small adjustment" needed. Glad you got it fixed