problem/3-brush Generator conv. to 2-brush

May have gone over my head here, but I tried it anyway. Rebuilt my early 8N 3-brush genny & attempted to convert it to 2-brush by doing the following: removed the 3rd(adjustable)brush & spring, tied the unused lead(from that brush)onto the field brush screw, installed a late 8N Vreg, hooked up the genny's arm., field, & grd posts to the corresponding Vreg tabs.

Where did I go wrong? The genny's not charging. Battery is new & good, lights work, tractor starts 1st time. I have polarized the genny numerous times. I tried putting VOM leads from battery + to each genny post(tractor running), no voltage from any of the three.

Just to make sure I'm not crazy, can somebody take a look @ the attached pic & tell me which genny post is arm., fld, etc.?

Jeff

Use a regular 8N voltage regulator. It should have labled terminals & 4-wires; 2-heavy BATT & ARM wires and 2-skinny wires FLD & GND that go to the gennys barrel studs..... ...Dell

Thanks for the "brass tacks" evaluation. I'm taking a copy of these posts on my next trip to fix it.

I may end up puttin' the 3rd brush back in it!

Jeff

Soundguy

The wire removed from the third brush could be routed out to a B circuit ( naa or hundred series )regulator field tab, ( for variable field power ) and then hook up the arm and battery connections as normal.

If you wanted to make this A circuit.. i think Bob is hitting on the right path.. One side of the field needs to go to arm.. the other side nees to go to the A circuit vr field tab to get ground.

Soundguy

As I recall the original connections inside the genny were: one brush went directly to the insulated post(arm.), one brush went to the windings(fld.), another lead off the windings went to the uninsulated post(grd), and the 3rd brush..... I can't remember!

I went back & re-read Coxter's post to me, he actually said to tie the old 3rd brush lead to hot brush(which I assume is the arm. brush?).

Jeff

If you have yours apart.. should be easy to see where the field hooks up. Like me and Bob posted.. to make it A-circuit, using a 8n VR.. field will need one side to be hooked to armature ( for field power ), and the other side routed out and hooked to the VR field tab to provide a vibrating variable ground...

In reviewing what you remembered, If the field has one lead going to ground.. then it was deffinately looking for field power via ( the other )the 3rd brush.. that's B curcuit setup...

Again.. to make a-circuit.. one side of field needs power ( armature ).. and the other side needs ground ( vr vibrating field contact ). simple as that.

Soundguy

Hope your getting minimal affects from Katrina.

Jeff

You know.. for testing.. take some jumper wires with you... You can full field the genny either way it is setup.

If one side of field is grounded.. power the other side by jumpering to arm.. that should give max charge.. ( this should be how it was setup oem.. one side grounded.. one side getting field power from 3rd brush )

If one side of the field is attached to the arm.. ground the other side... this gives you max charge..

Soundguy

Jeff

If you are using an "A" circuit regulator, the wire removed from the 3RD brush needs to be connected to the ARM terminal, and the other end of the field, which was grounded originally, needs to be reconnected to the "F" terminal.

Someone correct me here, if I'm wrong! I'm too tired to be trying to visualize this tonight!