Farmall H Generator Cut-Out

My 46 Farmall H had been running really poorly and I figured out tonight it was due to weak spark because of a bad battery. Put a new battery in it and it runs great now. So I went thru the Bob M troubleshooting guide for the charging system (it has not charged right since I"ve owned it). I went thru all the steps and found out the cutout is bad. (This is a 6V +grd system with generator.)

This is what happens...with tractor running 1/2 speed it shows a discharge on the ammeter. When I momentarily jump the BAT and GEN terminals it starts charging nicely. I get 10A in H and 4A in L. With the lights on the charge dips down then recovers quickly. BUT...if I lower the throttle to idle the charge goes back to negative, and when I go back up to 1/2 speed it is still negative unless I jump the BAT and GEN again. This means the cutout is bad, right? Is there anyway to repair the cutout or is it best to just buy a new one? How is the cutout supposed to work?
Thanks for your help.
Justin

Did you polarize the genny?

Justin, Open the VR and clean all the contacts and check again. Before you go buy a new one.
sometimes just some corrsion on points will stop it from working. oldiron29

You can clean the points to see if that helps or do as many have and ground the field and run it that way. If you ground the field you mite need to adjust the third brush so it doesent charge too high. Yhose old Delco Remy cut-outs arent available anymore you will have to replace it with a regulator if you take that route just make sure the new regulator is pos ground and also get the # off your generator so you can get the correct regulator.

That 10 amps High Charge and 4 amps Low Charge sounds like your genny and light switch etc are all FINE and I agree the cutout just isnt working and/or latching and holding in correct.

The VERY FIRST thing I would try is to insure a clean brigth shiny good ground (to genny if its genny mounted or metal frame member otherwise) to the Cutout !!!!!!!!!!! See if that cures the problem?????? You mighty also remove n wire brush shiny and re attach both Cutout leads (BAT & GEN/ARM) and likewise at the ARM and FLD on the genny.

Next thing (after a good cutout ground is established) if possible remove the cover and clean/buff/polish the relay contacts no more abrasive then required and see how she works then???

You ask how is it supposed to work??? The relay is normally open/unlatched and ONLY when the gennys voltage exceeds battery voltage it closes/latches shut and stays there until the gennys voltage lowers (like when you shut tractor off or at real low idle). If it has a poor ground or burned contacts or a bad relay winding (series or shunt) it may NOT act accordingly.

It can easily be replaced with a mechanical unit (suitable for 6 volts and Positive Ground remember) and some folks use a solid state replacement which are usually bi polar and work at EITHER ground if wired correct.

NOTE I guess it may be possible for a genny problem such as worn brushes or weak sticky brush hold down spring assemblies or a oiled carboned commutator to cause some of your problems but I'd suspect the cutout first as its easy to replace and not all that expensive. It probably wouldnt hurt as preventive maintenance to inspect and exercise your brush hold down springys, brush length, and clean the gennys commutator just in case while youre at it. That and a good grounding of the Cutout and a light clean/buff/polish of the relay contacts may cure all your problems woooooooo hooooooooooo

John T

Yes I did polarize it....several times. Thanks.

John T,
Thanks a bunch...I will go around and clean up all the wire connections and also the cutout contacts to see if that will help. I did have the cutout open and it looked pretty clean in there. Will also check the brushes and commutator. Thanks for the great suggestions!
Justin

I had a similar problem with my Super A at one time. I tried cleaning up the cut out relay contacts etc, but for all the messing around I did it was way easier to just get a new voltage regulator (not a cutout relay) adn wire that baby up. In my opinion the voltage regulator is a better way to go altogether that the cut outs

1)Unhook the battery 2)Clean the points on the cutout 3) Be sure the cut out is GROUNDED

A person below suggested full fielding the generator. That will not correct a cut out problem.