voltage regulator

Is there ant way to test a voltage regulator? I'm getting 15+volts out of the generator and just a little over 12volts at the batteries with the engine at 1800rpm. 3000 diesel tractor.

You need to trace the wire from the generator to the battery. If you are using a digital VOM, it may be reading incorrectly. Analog (needle) type are better on older equipment. That voltage drop is not good. So there is a faulty terminal connection, or too thin a wire in the system. The VR is not yet a suspect, Check the wires/connections. JimN

Im thinkin along the same lines as Jim. I dont think the genny is actually getting connected to the battery, maybe because the VR"s Cutout Relay isnt closing. If it was the gennys output would be near the same as that on the battery..... Use a lil jumper wire and momentarily connect the VR"s BAT over to its ARM/GEN when shes runnign and then measure the batetry voltAGE. If the genny is good at fast RPM the battery voltage should rise form its normal 12.6 to the 13 to over 14 volt range.

For the VR to work it needs a good ground, check thAT. iF EVEN WITH TEH vr"S bat AND gen/arm jumped dont make her charge when shes at fast RPM, see what happens if you jump the Gennys or VR"s FLD to ground??? If it charges then the VR is abd or not well grounded. With the BAT jumped to GEN/ARM (relay by passed) and FLD grounded the VR is out of teh equation so if still no charghe the genny is bad

Im not at home so cant post my Troubleshooting Procedure but if you search on the Farmall or Deere boards you can finds John T"s Troubleshooting Procedure.

The open unloaded output of a genny like if NOT connected to the battery cuz the VR"s cutout relay isnt closed dotn mean too much, its to what voltage it can raise a battery that matters. if its weak it will never connect to teh batetry via the VR cuz the cutout relay never latches in. Find my Torubleshootign procedure it will help

John T

If it is a Ford (model number seems to indicate) it could be a "B" circuit. They have power to field from regulator, do not ground the field terminal it could be smokey and incorrect. Check the manual to make sure of the Gen type. JimN

OOps my bad, fer sure some (but I dont know which ones) of those dern Fords are indeed Class B

John T NOT a Ford man

I accidently made that mistake when i was trying to reach around with a test probe. Ended up smoking the ground.