Farmall H Generator Revisit...bonehead mistake!!

Well guys I'm officially a bonehead. Today I was taking your suggestions to clean up all the wire connections related to the generator and cutout. Good news is the generator brushes and commutator looked good inside and I found an adjustment screw on the cutout which I believe I could have adjusted to make it work better.

Problem is...when I put it all back together I mistakenly mixed up the wires going to F and GEN on the generator. So essentially the output of the cutout was going to the F side and wire to F was on the GEN. I had started it up and was running it 1/2 speed, jumped the cutout and when I did that the ammeter pegged negative and the jump wire got real hot. I shut her all down and I think I saw a bit of smoke out of the generator.

So...did I screw up the generator now??? I put all the wires back the right way and I'm not getting any charging at all now.

Geez I'm a dummy.
Justin

You ask did you screw up the generator???

Wellllllll if you let the smoke out of it theres a good chance YES, maybe the Fields burned open or shorted out!!!!!!!!!!!

Heres how to determine if the Gennys is good:

TO DETERMINE IF ITS A GEN OR VR OR CUTOUT RELAY PROBLEM

5. a) VOLTAGE REGULATOR SYSTEM: With the tractor running, temporarily ground the Gens Field post to case. If she charges then but NOT otherwise, the VR may be bad, or a wires missing from VR's Field post to the Field terminal on the VR, or the VR isn’t well grounded.

b) IF IT’S A CUTOUT RELAY SYSTEM and she charges only if you dead ground the Field but NOT otherwise, its either a bad switch or the switch isn’t well grounded or else the wires bad or open from the Gens Field post up to the switch. INSURE THAT GOOD SWITCH GROUND AND WIRING

6. If she still don’t charge, leave the Field grounded and jump a wire across from the VR or Cutout Relays BAT terminal over to its GEN terminal (jump by passes the cutout relay) and see if she charges. If then but not otherwise, a VR's cutout relay isn’t working correct (maybe points burned/carboned) or a Cutout Relays NOT working or not wired correct.

7. With the 2 steps above, you have basically by passed the VR or Cutout relays functions, so if she still don’t charge, you're left with a bad battery or wiring or the Gen itself.

8. MOTOR TEST. You can Motor test the Gen. If its grounded and you remove the belt and apply hot battery voltage direct to its ARM Post and have the Field Post dead grounded to frame, it should motor n run well (Armature n Brushes and Commutator likely okay). Then, if you next remove the Fields ground and it speeds up some, the Fields probably good. If it passes both those tests, it should charge, and if not, it may be a wiring or battery or grounding problem. The hot battery voltage may be taken off the VR's BAT terminal or the starter post or the battery itself for this test.

John T

Thanks John...I basically did thru steps 7 ast night with no charge (2 nights ago I go charge whn I jumped the VR, before I screwed up the wiring!!) So I will try the motor test today. If motor is screwed up...what kind of a place will rebuild these and what can I expect to pay?

Thanks.

We have a local shop that does them but I don't recall the cost, as it has been a while. You can get a rebuilt one from this site for $200, or you could take this as a sign that you should change to 12V and get an alternator for $50 at NAPA. I'm sure there are also people who do it by mail if you're not in a hurry.
Zach

Unfortunately, theres not many old fashion Genny repair shops left, so youre stuck with a new or rebuilt genny at retail grrrrrrrrrr. My first guess would be you burned open or shorted one of the field windings, not too expensive to replace them and turn the commutator (less then $100) if theres a shop OTHERWISE pay $100 AND MOREEEEEEEEEEEE

Kenneth at Classic Generator in Texas does a superrrrrrrrrr job

If she dont charge with a grounded Field my Motor Test can show if the genny is bad WHICH I SUSPECT IT IS and would guess she will fail the test to speed up when the FLD is ungrounded???????

John T

An update...jut ran your test and it won't turn at all. I did verify I had a ground on the F and 6V on the Arm and it won't turn at all. Inside it looks like the wires ot the brushes are pretty shot. Anything simple it could be that I could fix, or am I destined for a new or rebuilt one?

Thanks again for all the help.

I had to have the 6 volt generator on my Super C rebuilt due to a bad armature in 2005. Looking at my receipt I see the parts (armature and 3 brushes) were $71.00 and the labor was $18.00 for .4 hour at our local generator/alternator shop in town. As I recall the shop had to try several sources before locating the armature which was shipped in. The generator has worked fine ever since. $100 might be a starting figure at this point depending on the prices in your area. Good luck, Hal.