Hey gang,
Changed out the voltage regulator on the 99 sportsman 500 due to spuratic voltage jumps (lights were dimming then bright back to dim and voltage ranged from 12 volts down to 8). The new regulator seemed to fix that issue. My concern is at idle I am only getting about 12.2 volts and if I throttle up a bit I get 13.5 volts. If I turn on my headlights at idle the voltage is 11.5 volts and throttled it will get to about 12.4 volts. Shouldn't I get more voltage at idle with nothing drawing power? I was thinking it should idle at least at 13.5-14 volts right? Ideas?
The battery is a sealed AGM and only a year old. Thanks in advance

 

Most of the older models really begin to charge once they're off idle.Voltage can drop even to the point of below normal battery voltage if enough equipment is turned on while machine is at an idle.The newer models and charging systems charge faster and most do charge 14-14.5 volts at idle.Just stronger improved electronics. Even the old manuals on charging tests show that between 3000-4000 rpms battery should be receiving 13.6-14.5 volts.If you're in this range you're ok.

 

Well I hooked a voltage meter to the battery and drove the ole girl around. Here's my findings (neighborhood riding at about 10-12 mph mind you): she stayed between 12.7-13.1 volts most of the time;however, I noticed my speedometer digital display that shows hours, etc was constantly go on/off at random. While it was "on" the voltage was as listed above. When the digital readout was off the voltage would drop to appr. 12.1-12.2 volts and stay there whether I throttle up or dropped to idle. Once the gauge came on the voltage went up to 12.7-13.1 again.
I did rev the engine in the driveway and got the voltage to 13.3 but didn't want to make the neighbors mad but it was climbing to the lower end of your mentioned scale of 13.5-14.4. When i shut the ATV off the battery maintained a 12.27 voltage.
Any ideas on what I have going on?

 

Even though the agm battery you have is only a year old,load test it. Don't know what brand you have ,but after my Yuasa ytx14ah died after about 6 1/2 years or more I went cheap. Didn't want to drive 50 miles back to the shop and get another one at cost,just picked up an agm at Batteries+ close by. I've already taken it back and got another one as it wouldn't hold a charge on the tender.
If your battery load tests good,then possibly this particular regulator may be charging all it's going to. Plus you can do a stator charge coil test and an alternator out put (ac amperage) test from the manual. Shows it should put out at least 5 amps.Anything less than that could be a weak stator charge coil.This might help you narrow down as to why the lower than normal charging readings.

 

Ok thanks. I will pull it and have a load test done. What would explain the digital readout going completely off then on then off? Perhaps a short in the speedo itself?

 

Possibly a short in the speedo wiring or in the connector itself. A simple connector pin not making good contact can cause erratic operation.Plus you can add some electrical grease and see if it helps.

 

Will do. Thanks again!

 

Well here's the verdict:
After cleaning the main ground with some sandpaper, I now have a idle voltage of 13.03 and a running voltage of 14.3 volts in the neighborhood. Seems as if that ground was the culprit. I also took a small flat head and bent the pin receivers in the speedo connector to make them
Tighter and added some bulb grease. No more flickering at this point with the digital gauge. Thanks Tech!!

 

Simple things are what make you pull your hair out at times.Most of the time you're overlooking the problem thinking it's something larger. Like the old saying, can't see the forest for all the blame trees..