Generator problems

[Plowboy48]

Sorry bother with this ? I was always told you can test generator by take cable off if it stays running it's charging. Dose that work on a distributor to I took mine off and it died and battery dead if so how easy is it to rebuild my self or do I need get hole new generator or replace little regulator on top.(p.s with distributor will die anyways. When lights on it goes discharge but when no lights stays at 0 don't even move to right close to ten like it use to. Any ideas. Thanks Tyler.

[Puffie40]

A quick test for the generator is to take the belt off, disconnect the voltage regulator and hook up battery voltage to the A and F terminals. If the generator spins without much effort (it will be a fairly slow speed), then the generator is okay and can be cleaned up.

[Plowboy48]

Ok it won't even charge my battery I thought.mite need polarize so run a jumper from battery to a and f

[Stanton]

Ok it won't even charge my battery I thought.mite need polarize so run a jumper from battery to a and f

Might want to double check before polarizing as to which terminals to hook up. Owner's Manual on the subject is here:

http://www.cleancomputes.com/Cub/Cub%20 ... age-40.jpg

I wouldn't want you to fry something...

[Matt Kirsch]

It could be any of several things. I personally have never had good luck just guessing at it, and generators RARELY need to be polarized in my experience.

This is a generator troubleshooting procedure from another forum that I have printed out and stuck in the pages of my Cub's service manual:

TROUBLESHOOTING CHARGING SYSTEMS

ARE YOU SURE THE AMMETER IS WIRED CORRECT AND WORKS????? If you turn the lights or ignition on (if coil ignition not a mag) when she’s not running, the ammeter should swing over to the - discharge direction, does yours??? Are BOTH the ammeter terminals reading hot battery voltage?? They MUST !!!!!!! There’s but one wire on the ammeters Supply (from battery/starter) terminal while its other Load terminal wires to the BAT terminal on a Cutout relay or VR PLUS wires to feed loads like lights or ignition, UNLESS where a 4 terminal VR is used, and if so lights n ignition are fed from the LOAD terminal on the VR.

To Polarize the Generator, first temporarily dead ground the Gens Field post to case/frame, then momentarily flash jump a wire from the Cutout Relay or VR's "BAT" terminal over to its GEN/ ARM) terminal and you ought to get a small spark. Same things accomplished by momentarily flash jumping a hot wire (BAT terminal on Cutout Relay or VR or starter post etc) direct to the Gens ARM post to get the spark.

TROUBLESHOOTING A CHARGING PROBLEM IN CLASS A DELCO TYPE SYSTEMS

1) For a good working Gen to get to and charge the battery, it has to have a path usually from the Gens ARM post,,,,,,,,,,To and through the Cutout Relay (between its GEN and BAT terminals, regardless if on a VR or Relay),,,,,,,,,Up to the Load (NOT to battery) side of the Ammeter,,,,,,,,,To and through the Ammeter,,,,,,,,,,From BAT side of Ammeter to ungrounded battery terminal, often via the starter lug post. Is yours wired that way or equivalent ??? The ammeter should read hot battery voltage on BOTH terminals, does yours??? Even if an ammeter were stuck (but still continuous) as RPM increases the battery voltage should rise from 12.6 to near 14 volts and/or the lights glow brighter (half that on 6 volt systems). Have you tried that in case the ammeter isn’t working right?????

2) If the above is so, the BAT terminal on the VR or Cutout Relay MUST ALWAYS READ HOT BATTERY VOLTAGE. Does yours??? If not, the Gen cant get to and charge the battery.

3) The Gen to VR (if it has one) wiring is as follows:

BAT on VR to ammeters load (NOT battery) side

ARM (or GEN) on VR to Gens Armature post.

FLD on VR to Gens Field post.

(L) Load (if you have a 4 wire VR) up to BAT supply input terminal on switch to feed loads like lights and ignition.

WIRING ON CUTOUT RELAYS: They wire BAT side to ammeters Load terminal,,,,,,GEN side to gens Armature post. On cutout relay systems, the Gens Field post is wired to the light switch where it gets a dead ground for high charge or a resistive ground for low charge. Therefore, there must be a good connection from the Gens Field post up to the switch PLUS the switch is good and it’s well grounded !!!!!!!!

4. THE GEN AND VR OR CUTOUT RELAY MUST BE WELL GROUNDED AND THE BELT GOOD N TIGHT. If any doubt, run a ground wire from the grounded battery post or clean solid frame member direct to the Gen and see what happens????????????????????????????

NOW, if the Gen and VR are grounded,,,,,all is wired correct,,,,,,,,BAT terminal on VR or Cutout Relay is HOT,,,,,,,,Belt is tight,,,,,,,,,Ammeter is good n continuous n works but she wont charge, have you had the batteries tested lately????? Is there electrolyte above all the plates and no cells have a gray or milky appearance?????? A bad battery may not accept a charge you know!!!!!!!! If the battery checks okay, proceed below to see if its a Gen or VR problem (AFTER you have insured the wiring per the above)

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.

9. Typical Gen problems may be the brushes are worn down or the hold down spring assemblies are stuck/corroded/dirty and arent pushing the brushes tight down against the commutator. Check those things out. Worse may be bad fields or armature etc. Air and WD 40 etc can clean and free them, the hold downs must be free n snap and hold the brushes DOWN TIGHT and they cant be worn down too low.

SUMMARY: Check the wiring,,,,,the grounds,,,,,,insure BAT on VR or Relay is hot,,,,,,,check battery (maybe load tested and Specific Gravity checked),,,,,,,,,good tight belt,,,,,,,insure ammeter is continuous (BOTH sides HOT),,,,,,see if battery voltage rises above 12.6 (half that for 6 volt system) and/or light glow brighter,,,,,,,,,do the Field and cutout relay VR by pass checks,,,,,,,,insure the Gens brushes arent worn down and the hold down springs are free n clean and push the brushes down tight,,,,,,,,,,,check the connections,,,,,,,,,try the Gen Motor Test to see if its good.

You may just have a bad battery or bad ground or connection if the Gen and VR or relay are okay. Good Luck n God Bless, let us all know.

John T Nordhoff in Indiana, retired Electrical Engineer

[Plowboy48]

Well tried polarize the gen I didn't even get a spark amp didn't move to the right and tried off f mine also got a cutout on it so either cutout bad or gen is bad

[birddog]

I was always told you can test generator by take cable off if it stays running it's charging.

You don't say here which cable you mean, but if you mean the cable at the battery, the answer is yes, most of the time. It can depend how your tractor is wired though.

Dose that work on a distributor

Only on a distributor. A mag doesn't need a battery to run.

how easy is it to rebuild my self

It depends whats wrong. Generally a good cleaning and maybe new brushes is all it needs, anything more it's best left to a pro, or get a new or rebuilt unit.

Check the How To Forum electrical section. http://www.farmallcub.com/phpBB2/viewforum.php?f=140 I've got a couple threads there on testing and cutout/ VR adjusting.

[Plowboy48]

Ok what is the normal voltage in a 6 volt when tractor not running and is it when it is running I polarized I got power to my armature on lite switch got power on both post on my amp gauge I was wondering if my gauge was bad.

[BIGHOSS]

A fully charged battery will check at 6 volts by a good voltmeter, when not running. When running, it should check around 7-7.2 volts. I don't worry about the amount of charging, just so there is a definite increase in voltage when running at 1/2 throttle or more.

[Plowboy48]

Boss hog I tested mine it said 6.2 I belive not running well then I started it bout half throttle off on with digital but bounce around cause gen off and on lots movement. So found my old school for older check on dc 10v it's read can't remember but when I started it agian half throttle stayed did move any. We'll I left it hook up when I started it needle went down cause it pulled juice then when it started back to same spot. So I say it's cutout or gen rebuild. But when I tried polarize it it went over to discharge side. I was going try the field but don't know where to ground it I'm to point of giving up I just got my tractor back missed all later year. I'm not going miss this year.

[Plowboy48]

Then I ran it for awhile plowing today and when I parked I checked agian still 6.2.