Short answer is no. The regulator grounds the field terminal inorder to complete the circuit and make the generator make voltage.
I just recenty went through troubleshooting my 6v system and I'll pass along what I found out. keep in mind this applies to a 49 3100.
1) There should always be battery voltage on the reg's "Bat" term.
2) The reg's "gen" term connects to the gens "bat" or "arm" term. It should be a home run wire. Make usre theres continuity on the wire between the gen & reg.
3) The reg's "field" term connects to the gens "field" term. Make sure the home run wire has continuity.
1st read the battery voltage, this is your reference mark.
To test the gen, connect up a voltmeter on the gen's "Arm" term.
Start the engine and observe the volt reading. Should be atleast bat voltage. increase rpm and the voltage should rise to 7 or more volts.
Now connect the meters pos lead to the reg's "gen" term and repeat test. should be the same as before. If not theres a wireing problem between the reg & gen.
IF you get no voltage or low voltage, make up a jumper and with the volt meter connected as before temporarily ground the gens "field" term and increase rpm. YOu should see atleast 7 volts.
If not the gen is not producing voltage and needs rebuilt.
If you do get voltage, move the meters pos lead to the regs "Bat" term and repeat, the test should read the same, if not theres a wireing problem betwwen the reg & gen.
The reg has 3 relays. from right to left (when seated in the cab) the 1st is the cutoff relay. It provids the connection between the battery & gen. It is open when the gen isn't producing voltage to kepp the battery form dischargeing back through the gen. It closes when the gen's output voltage is higher than the battery voltage.
The 2nd relay controls the voltage produced by the gen. It has 2 windings that work against each other to control the voltage.
The 3rd relay controls the current flow by controlling the ground being applied to the gen's field term.
If the battery is dischargeing it could be in the reg, the cutout relay could be sticking closed. You can pull the cover and depress the relay contact down. if it moves down it was sticking in the up "make" position, which will discharge the battery. beaware that theres voltage on those contacts so be carefull. You could burn something up.
I haven't read the whole thread but it seems you need to determine if the battery is dischargeing when the engine is off.
This is a simple test. You need a tail lamp or running lamp bulb.
solder 2 leads to it. one lead to the soldered tip of the bulb and solder the other lead to the bulb's metal case. place one lead on battery pos and the other on battery neg and it should glow. this will test that you've wired it right.
Now disconnect the battery's pos terminal and clamp or wrap one of the test bulbs leads to it. Connet or wrap the other test bulb lead to the batterys pos terminal. If the lamp glows you have something drawing power when it shouldn't be.
If the lamp doesn't glow either turn the ign switch on or pull the lights on to make sure you have connected correctly. The lamp should then glow and power will supplied to the device you turned on.
If the lamp passes the tests but isn't on w/everything off you don't have anything pulling power when the engine is off.
Beaware that a small draw, will still pull a battery down and a small draw will barely light the lamp under test.
Good luck
Dave
