Starter/Generator Voltage Regulator wiring

[KC9KAS 4,741]

I am trying to connect a new voltage regulator to a starter generator.

I have looked at every thread on Red Square dealing with S/G VR's as well as diagrams on the net.

My regulator has 4 terminals.

F-  Connects to the Field on the S/G

G- Connects to the A on the S/G

L- Lights or accessories

B- Battery

 

On the A terminal of the S/G the "start" wire should be connected either from a heavy duty switch or solenoid.

 

Now comes my dilemma....The G terminal on the VR is also grounded to the VR mounting, thus grounded to the S/G and the frame and finally the negative side of the battery. 

It appears to me that there will be a "dead short" when activating the "start" mode. Positive to the A post that is also wired to the G on the VR, thus ground.

 

Am I missing something or is my VR not right? The VR says "for positive OR negative ground". I am dealing with negative ground.

[953 nut 55,708]

Take a look at this.

[rmaynard 15,580]

I'd look in an older Kohler K-series service manual, electrical section. It shows the wiring for a starter generator setup.

 

[953 nut 55,708]

Older Wheel Horse wiring diagram seems to match up with Bob's post from Kohler.

[ol550 830]

Does your new regulator have another terminal on the bottom?  Possibly the A terminal.

[KC9KAS 4,741]

48 minutes ago, 953 nut said:

Take a look at this.

 

48 minutes ago, rmaynard said:

I'd look in an older Kohler K-series service manual, electrical section. It shows the wiring for a starter generator setup.

 

 

16 minutes ago, ol550 said:

Does your new regulator have another terminal on the bottom?  Possibly the A terminal.

Fellows. I have looked at everyone of these diagrams multiple times.

The 4th terminal on the bottom of the VR has a "G" on it and it goes to the "A" post on the S/G....as does the start wire. The issue I see is a circuit from the positive side of the battery through the solenoid to the starter feeding + voltage to the G terminal that is grounded causing a dead short. 

[953 nut 55,708]

Is the "G" terminal actually grounded or is it just labeled "G"?

[JPWH 6,090]

This is the VR on my 854.

[953 nut 55,708]

Found this wonderful drawing. The "G" terminal is GENERATOR!

[KC9KAS 4,741]

7 hours ago, 953 nut said:

Is the "G" terminal actually grounded or is it just labeled "G"?

It is labeled "G" (for generator), but when I did a continuity test, it was grounded.

[gwest_ca-(File Mod) 11,090]

Most likely a high impedance ground through the windings in the generator. Can you measure real low ohms? It may give you 1 or 2 ohms where a chassis ground will give you 0 ohms.

 

Garry

[KC9KAS 4,741]

2 hours ago, gwest_ca said:

Most likely a high impedance ground through the windings in the generator. Can you measure real low ohms? It may give you 1 or 2 ohms where a chassis ground will give you 0 ohms.

 

Garry

This may be what I am seeing.

I did speak with a mechanic at a tractor dealership this morning. I showed him the wiring diagrams and explained what I was talking about.

As he looked at the diagram, he said it was a "standard" diagram for s S/G VR setup and it will work if the S/G and VR are all working properly.

I do have to polarize the VR before I attempt the start the engine.

 

I know all electrical items work/operate on SMOKE, and if the smoke comes out, they are shot!!!

Thanks to all that responded and tried to help me understand what I had and was dealing with!

[gwest_ca-(File Mod) 11,090]

I recall SOI stating the polarization is not necessary. Once you use the starter the voltage regulator is polarized.

 

Garry

[953 nut 55,708]

 

[KC9KAS 4,741]

@953 nut and @gwest_ca Thank you very much for adding this information!

 

I miss SOI...anyone know what happened to him?

[Handy Don 12,411]

On 11/17/2017 at 5:18 AM, KC9KAS said:

It is labeled "G" (for generator), but when I did a continuity test, it was grounded.

 

On 11/17/2017 at 5:37 AM, gwest_ca said:

Most likely a high impedance ground through the windings in the generator. Can you measure real low ohms? It may give you 1 or 2 ohms where a chassis ground will give you 0 ohms.

 

Garry

I agree with Garry here.

Also, when checking resistance, always be sure to check both polarities (i.e. take two readings, switching the black and red probes in between--nearly all meters use DC to test ohms!)