Electrical issue BN

[Aasafetypilot]

My 6 volt generator (positive ground) with cutout will put out 7.5 volts, when tested (lead from gen term on cutout). But will not show a charge on ammeter (ammeter tests ok). When I check voltage on bat term on cutout, shows around 2 volts… when I jump between bat term and gen term (basically closing the points) shows discharge. I have the original cutout and a new Brillman one. Same results on both. If the generator is producing power, why can’t it get to the battery? I’ve wired according to the manual, battery is fully charged (6.2 volts) and wired properly. I jumped power to A term for polarization, but something is definitely not right. Thoughts?
Thanks

 

[Janicholson]

My 6 volt generator (positive ground) with cutout will put out 7.5 volts, when tested (lead from gen term on cutout). But will not show a charge on ammeter (ammeter tests ok). When I check voltage on bat term on cutout, shows around 2 volts… when I jump between bat term and gen term (basically closing the points) shows discharge. I have the original cutout and a new Brillman one. Same results on both. If the generator is producing power, why can’t it get to the battery? I’ve wired according to the manual, battery is fully charged (6.2 volts) and wired properly. I jumped power to A term for polarization, but something is definitely not right. Thoughts?
Thanks

The cutout must be grounded to work (both for the cutout component and (if used) the field connection. The F connection is through the light switch only if you have a 4 position switch. If that switch is not grounded, or the electrical box is not grounded, it will not produce. Jim

 

[Aasafetypilot]

Thanks Jim. I’ve been having a bit of a problem wrapping my head around “ground” in a positive ground system. I’ve run a jump wire between the switch, the electrical box and the mounting post, as corrosion prevented a good connection. My F term on the generator is connected to the switch (4 position) as shown in the appropriate wiring diagram. Just to confirm, with battery hooked up, engine NOT running, I should show battery voltage at the box, the switch, the F terminal and the cutout if a voltmeter is connected in series to the neg battery post… correct?
Thanks
Jim

 

[Janicholson]

Thanks Jim. I’ve been having a bit of a problem wrapping my head around “ground” in a positive ground system. I’ve run a jump wire between the switch, the electrical box and the mounting post, as corrosion prevented a good connection. My F term on the generator is connected to the switch (4 position) as shown in the appropriate wiring diagram. Just to confirm, with battery hooked up, engine NOT running, I should show battery voltage at the box, the switch, the F terminal and the cutout if a voltmeter is connected in series to the neg battery post… correct?
Thanks
Jim

Yes. From the Negative battery post every thing attached to the tractor except some of the inner workings of the regulator should show voltage. The on off switch (if a mag) should show voltage, it is a grounding switch. The hot side of the ignition switch on a distributor/coil ignition should not show voltage (it already has the same polarity as the negative pole!)

 

[560Dennis]

As above suggest Check the positive grounds to chassis , . I had the corrosion vat the control box three bolts to chassis at the differential , that made for a interesting time
you need positive ground cut out ! Field wire broken at light switch !
volt meters voltage to ground , had a busted battery cable , looked good , got nothing thru it .

 

[Aasafetypilot]

Thank you Jim and 560Dennis -
All my grounds check out. I’m out of town for a couple of days, but I plan to check voltages at the generator, cut out and switch with engine running, perhaps take the cut out then the switch out of the circuit altogether to isolate the problem. I’ll let you guys know and check back for comments later in the week. Thanks!

 

[Aasafetypilot]

Gentlemen… hopefully electrical experts… here’s the latest.
6volt positive ground with cutout, magneto and lights. New wiring harness from Brillman. Wired exactly as illustration 71 (page 76) of Operators Manual.
Engine OFF - Battery voltage 6.22v
When checking grounds, Electrical box 6.22v
Switch (screw) 6.22v, chassis (various) 6.22v, generator mounts (3) 6.22v, coutout mounting screws 6.22v, “F” term and “A” term on generator both 6.22v, “BAT” term on cutout 0v (points open). Top contact of points 6.22v. When lights turned, ammeter (new) shows discharge.
With engine running…
Battery voltage 6.7v, ammeter shows DISCHARGE, points closed but opening and closing rapidly (no, there is no voltage regulator), “A” term shows 7.2v, “F” term shows .54v
What is going on??? Any thoughts appreciated.

 

[Jim Becker]

First off, when checking voltages it is normal to ground one test lead and use the other to check for voltage at the various points you are checking. You evidently are leaving one probe on the battery hot terminal and probing with the other. If that is what you are doing, your readings seem pretty normal but you are leaving portions of the circuit untested. Also, it doesn't really confirm good grounds. A high resistance in a ground connection will usually pass battery voltage.

Your problem when running suggests to me that you did not polarize the generator and it is currently wrong. Correct this by taking a wire and momentarily jumping a wire from the cut-out BAT to the cut-out FLD terminal. Do this with all wiring connected and the engine NOT running.

 

[Aasafetypilot]

Thanks for the thought. So I polarized the generator as suggested, no change. My resistance readings on grounds are less than an ohm. I really cant figure out why battery voltage (6.22) goes up to 6.7 with engine running, but shows a discharge on the ammeter. Also - the points tend to stick closed on shutdown, also showing a discharge…

 

[Aasafetypilot]

And you mentioned I was leaving portions of the circuit “untested” - can you elaborate?
Thanks

 

[caterpillar guy]

Sounds like the wires need to be swapped on the ammeter if changed around in this process.

 

[Jim Becker]

And you mentioned I was leaving portions of the circuit “untested” - can you elaborate?
Thanks

I don't believe it verifies any of the circuit from where you pick up voltage at the battery and the BAT connection of the cutout.