Voltage on my 310-8 always reading high

[boovuc 1,090]

Tried two different batteries that were charged, Temp doesn't matter since it charged high in the fall and now winter. Low RPM's reads above 12 volts. Full throttle reads 16 or more volts. Doesn't even blink when the lights are turned on or off.

The battery doesn't get hot nor are the battery leads hot or even what I would call warm but I don't believe this is quite kosher.

Opinions and trouble shooting order please? (Advice always saves me time which is a premium lately)!

Thanks!

[Jim_M 178]

Sounds like a bad voltage regulator, but then again the gauge could be wrong. If the battery isn't losing water and you're not blowing bulbs I might be inclined to suspect the gauge. Can you check it with a hand held multi meter and compare the 2 readings?

Edited January 26, 2013 by Jim_M

[sorekiwi 761]

Your symptoms are vaguely ringing bells, but unfortunately I dont remember the details. Hopefully Chuck will see this one.

This is the Magnum without the seperate Regulator isnt it?

[sorekiwi 761]

Here is one thread:

There is another one I am thinking of, but I havent found it yet...

[Save Old Iron 1,563]

Boo,

in the colder temperatures of winter, a higher charge voltage is actually a plus to the life of the battery. Standard thought on a "correct" 14.5 volts from the regulator will result in undercharging a battery in the winter months.

Having said that, the advice from Jim and Mike is right on for a 3 amp stator system.

Mike pointed to a post I made a while back about inserting additional diodes into the charge line to decrease the charge voltage. I acquired a 211-5 a year or so back that insisted on settling the charge voltage in at 16+ volts. I inserted 2 additional 3 amp diodes in series with the original diode and the voltage dropped to 14.8 at top engine speed. The battery will survive much longer at this reduced charge voltage. Any voltage above 14.5 will start to break down the electrolyte in the battery and "boil off" water in the battery. Not "boil off" as in a pot boiling on the stove but slowly breaking down the hydrogen / oxygen bonds in the water so the electrolyte slowly disappears from the battery in the form of released gasses. This of course is a slow process, but may take a battery capable of 4 years on the tractor and decrease the useful life down to a year or two.

Radio shack sells the 3 amp diodes and the heat shrink tubing to effect the modification. I can vouch for the fact that it works. The reason it does work is a well known electrical property of power diodes - constant VOLTAGE drop across the diode under varying CURRENT flows. Each diode will maintain a constant drop of 0.6 to 0.7 volts under a very wide range of current flows.

[boovuc 1,090]

Thanks, guys! I'll get the VOM out and confirm the gauge reading.

If confirmed, we'll take a trip to RS.

Thanks!

[boovuc 1,090]

Hi Guys,

 

My 310-8 is overcharginging. I'm getting a good 16 VDC at the battery. (Same as I am getting through the volt gauge).

The white wire from the stator is where I "should" find the factory diode but unless I have lost all desterity in both hands, I could not "feel" the diode in the wire. Does anyone have an exact location where the diode is? (Considering it hadn't been messed with by the PM)?

 

Thanks,

[TT-(Moderator) 1,127]

 

[boovuc 1,090]

Thanks, Terry. I'll take a look past that connector from the stator on Sunday

[Wheel-N-It 2,967]

I know we are talking about Wheel Horses here, but I did have an overcharging problem on my 2000 harley davidson fxst. Right off idle it would charge up to 18vdc. Turns out it was the regulator. I replaced that and the battery. Problem solved.

Just saying this to show that an overcharging problem can (yes) be the regulator.

[leeave96 487]

Van,

 

I don't remember seeing a Harley when I was down there last Summer.  Must have been blinded by all the red...       

 

Thanks!

Bill

 

[boovuc 1,090]

Hi Van,

 

The 310-8 and others of that series in the late 80's have a little 3 amp charging system that doesn't use a rectifier/regulator. Such is mine!

I had a 1975 Sportster for decades and I needed to change out that AC Delco regulator in it. (Among a whole lot of things to that AMF manufactured POS).

Save Old Iron would have pursued another career path if he had owned it! It was easier to just hook the thing up to a battery charger each night then to track down the electrical snafus in that two-wheeled sh**-hauler. And this is the nicest I've talked about it in years! If you ever owned an AMF Harley, then you should know what "AMF" really stands for! 

 

Thanks,