farmall 450 voltage regulator ?

Wally67

Member
Hi everybody I am trying to diagnose a no charge and battery draining problem with one of my farmall 450's. The battery I have is old but will take a charge on the charger and work fine for a while when I hook it up to the cables in the tractor I can here the voltage regulator make a faint click with the ignition off. I started checking wiring today and found everything to be fine. With all the wiring disconnected to the regulator except the wire that runs from the starter main terminal with the battery cable to the regulator, still hooked up to the regulator I still get a click in the regulator ( the upper contact pulling close when hooking up the battery). Could the regulator be shorted internally causing my problems. I checked my other 450 and it does not do this and it charges fine.
Thanks for the help
 
I copied this link a few years back. I can't find the op so here goes. https://www.dropbox.com/s/futtmu331nmkbvr/generator%20testing.txt?dl=0
 
Gotta be a problem in the regulator. The click you hear when you connect the battery is the VR's cutout relay closing. It's not supposed to close until generator output voltage is higher than battery voltage. And when the cutout is closed without the engine running the battery slowly discharges through the generator.

Time for a new regulator!
 
The wire from terminal A on the generator runs to the GEN terminal on the regulator. The wire that runs from the lug on the solenoid with the battery cable from the negative post of the battery runs to the ammeter negative side then from the positive side of the ammeter it runs to the BAT terminal on the regulator. Thanks
 
I picked up a new regulator today and got it put on, it fixed my clicking problem when hooking up the battery but I am not 100% sure its charging correctly. I have between 14 to 17 volts at the GEN terminal of the regulator depending on the RPM but only 12.2 - 12.5 on the BAT terminal of the regulator no matter what RPM the tractor is running. Are these numbers ok for a fully charged battery or should I be seeing more voltage? Thanks for the help
 
If you have all the wires connected correctly you need to check that the regulator has a good ground. The voltage readings you gave would indicate the the cut out relay in the regulator is not closing when the generator voltage exceeds battery voltage.
 
Ok I will try running a wire from the frame of the regulator to the ground on the battery and see if that helps. I did pull the cover off of the new regulator when the tractor was running and noticed the top set of contacts were sparking like they were opening and closing very quickly. Thanks!
 
The use of a moderately inexpensive digital meter "VOM" is usually a difficult or impossible to read device. The meter is taking an instantaneous sample maybe 10 times per second (sometimes less). The voltage control in a generator/regulator system from that era is based on vibrating points in the regulator. The points chop the field into a mish-mash of spikey current flow that averages to control Gen output. The gen output is also affected by the brushes and commutator sparking and sliding between commutator bar contact. To say it simply it is electrically noisy. As the meter samples, it can be instantaneously five volts off of the averaged voltage, and that is what is displayed on the meter readout.
A $20.00 analog meter with a scale and needle is far more accurate for the purpose you are using it for because it samples continuously, and the needle mechanism causes a weighted averaging effect.
If working correctly, the cutout relay in the VR will be closed (conducting directly through it) above idle. resulting is the same reading on the ARM terminal as on the Bat terminal. If the two are still different when running, the VR might be the wrong one. I assume the F terminal on the VR is connected to the F terminal on the gen with no other things hooked there. Jim
 
I tried running a ground wire from the frame of the voltage reg. to the battery and no change in the ammeter reading. The voltage regulator I bought looks exactly like the old one and is labeled for 12 volt systems positive ground or negative ground and has the cross reference number that matches the delco number on CIH parts site . The F terminal of the voltage regulator wire runs to the F terminal on the generator with no other wires hooked to either post. What is the best test for generator out put on these? Thanks.
 

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