John Deere 70 regulator problems

My 70 has always started up good until this spring. Every time I would go to start it up I would have to use a battery charger. I was told that the voltage regulator was incorrect for the tractor. I know where to get a new one but the problem is that I don?t know how to put it back on.

I wasn?t the one who took the box off of the machine so I have no frame of reference as to how it goes on.

Also the left hand battery cable is broken and needs to be replaced. Is this just a simple fix or more complex?

Thanks for anything
 
Here are some generic connections. Did you try to Polarize the Generator ?? That should be done BEFORE starting the tractor.
The VR and Genny need good grounds.

For a 3 terminal (BAT GEN/ARM FLD) VR

GEN/ARM on VR to gennys ARM post
FLD on VR to gennys FLD post
BAT on VR up to the load (NOT battery) side of ammeter

For a 4 terminal (BAT GEN/ARM FLD LOAD) VR

GEN/ARM on VR to gennys ARM post
FLD on VR to gennys FLD post
BAT on VR to the load (NOT battery) side of ammeter
LOAD on VR up to light switch to feed 12 volt loads

If it don't work try my Troubleshooting Procedure

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


John T
 
"[b:654c4848f0][i:654c4848f0]I know where to get a new one but the problem is that I don?t know how to put it back on.[/i:654c4848f0][/b:654c4848f0]"

Take a look at the [b:654c4848f0]Lamps and Wiring</i>[/b:654c4848f0] diagram below.

cvphoto24300.jpg


Note the orientation of the regulator terminals to the inside of the tractor.

Also note the positions of both the A ARM post and F FLD post on the generator.

Take a look at the generator on "Big John" one of our Model 70 tractors.

cvphoto24302.jpg


Take a look at the illustration below of the regulator part no. [b:654c4848f0]1118792[/b:654c4848f0] designed for the Model 70 gas tractor.

cvphoto24305.jpg


Note that the regulator has three terminals.

From left to right are the BAT, GEN, and FLD terminals.

The [b:654c4848f0]BAT[/b:654c4848f0] terminal on the left is connected to a wire from the ammeter.

The [b:654c4848f0]GEN[/b:654c4848f0] terminal in the middle is connected to the [b:654c4848f0]A ARM[/b:654c4848f0] post on the generator.

The [b:654c4848f0]FLD[/b:654c4848f0] terminal on the right is connected to the [b:654c4848f0]F FLD[/b:654c4848f0] post on the generator.

Hope this helps.
 
To add just a bit more to all the good info and great pictures below, in the event you cant make out the posts on the Generator, on some generators the ARM post is the bigger of the two (Fld and Arm). The VR typically has clearly visible BAT (wires up to load (NOT battery) side of ammeter),,,,,,,,,,, GEN (wires to the bigger ARM post on generator) and FLD (wires to the smaller FLD post on generator). Just in case and to be safe I would Polarize the generator BEFORE starting.

NOTE Caution, the wire up to the ammeter that connects to BAT on the VR IS HOT 12 VOLTS so don't let it short to frame.

Many VR's are polarity specific IE labeled for wither POS or NEG ground. Your tractor was originally POS ground, use the correct VR

Make sure the VR and Genny have a good ground.

If it fails to charge work my Troubleshooting Procedure to find the cause.

Happy Memorial Day, thanks to all Veterans

John T
 

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