Voltmeter "Speed Swing"

[Tankman 3,523]

Voltmeter on my newly acquired 416-8, '85 model, swings rapidly,

At times, rarely, holds steady 14-16 volts.

Any ideas? Dirty connections perhaps?

[Wheel-N-It 2,972]

Check all your conections, run an extra ground from the voltage regulator to where the negetive cable connects to the chassis to insure you have the regulator solidly grounded. Then see what you got. Also check the AC voltage coming from the stator. You should have 28-30 VAC at WOT. Let us know what is going on with it after you do this.

Van

[Tankman 3,523]

Haven't done any PM yet but, had the Horse out.

At high RPM's, needle (pointer) stays put 'tween 15-16 volts.

[CRE1992 135]

When I was taking Auto Tech for 3 hours a day in High School, an automobile should charge it's battery at between 13.6vdc-14.3vdc. All of the tractors I have had in the past, charge between that also.

-Charles

[Save Old Iron 1,571]

Tankman,

I would start by using a multimeter set on DC volts to measure the same voltage the tractor voltmeter is measuring.

If the tractor voltmeter is jumping but the multimeter is steady, then the issue with the tractor voltmeter.

If the multimeter shows the same "jumpiness" and voltage reading as the tractor voltmeter, the issue is in the charge system.

An older battery will not absorb power from the charge system as it should and tend to show a higher voltage than expected. You can test, or have the battery load tested to confirm if the battery requires replacement. If the battery proves to be in good condition, the voltage regulator on the tractor may be suspect.

[TT-(Moderator) 1,162]

Not that it influences the erratic needle movement of the gauge, but I believe that engine has the 3 amp / non-regulated charging system.

[Tankman 3,523]

Not that it influences the erratic needle movement of the gauge, but I believe that engine has the 3 amp / non-regulated charging system.

That is correct. I purchased the 416 sight unseen, thought I would be receiving a 418. At the price, I am not dissapointed. This Horse is runnin' fine. Shipped to me with a 48" deck mounted, and a 42" deck (loose of course). The horse was parked under a barn leanto, semi-outdoors.

Just ordered new decals, installed a shift boot (dust cover), oil change, gear lube change, carb cleaning, and on and on, and so on. Lookin' good, running great.

[Save Old Iron 1,571]

I believe that engine has the 3 amp / non-regulated charging system.

Knowing that additional bit of info reinforces my belief in the possibility of a sulphated (defective) battery,

Check across the battery terminals with the multimeter - jumpy multimeter suggests battery issue or charge system issue.

A second step could be to swap out the battery to see if the response of the tractor voltmeter changes - meaning the battery is "too easily charged". A common characteristic of an abused, sulphated battery. What you are witnessing is the way a unregulated charging system responds to a lighter load - the voltage of the charge system goes up.

My 211-5 with the same style charge system would typically display higher than normal charge voltages with an aging battery. A second or even third diode wired in series with the original diode will lower the excessive charge voltage by .7 volts per additional diode.