kohler starter/gen.

hello--on a kohler single cyl. engine using starter/gen setup{delco?] was asked how to check charging system output. brother has one that cranks engine fine, but no charge. I know it also uses reg.] was going to suggest grounding F term. while running, but wasn't sure this was correct- thanks--paul-

Yes, grounding the "F" terminal on that unit will "full-field" it, making it charge at it's maximum rate. However, the "cutout" section of the voltage regulator needs to be functioning for any charging current to get to the battery.

Often, on those units, the little braided copper ground strips that bypass the rubber mounts on the voltage regulator will break, so the regulator is no longer grounded, affecting field current. Taking a look at them is a good place to start.

thanks Bob. -Paul.

Hi dieselpaul, yes Bob is right by grounding the field terminal will make the generator charge full rate which is infinite. Hook a test light up to your battery hot terminal (not the ground) then to the "A" terminal on the generator while it is running if it lights there is no generator output then ground you "F" terminal while it's running and see if the test light goes out if it goes out the generator is good. If the light goes out you have an open circuit between your "A" terminal and the amp meter or battery.-(circuit) (it"ll be most likely the regulator). I would say the generator is good since you say it starts the engine. If a generator motors it means it will generate also. The start circuit by-passes the voltage regulator when starting the engine. I've been testing generators like that for over 30 years. I read it in an old-old motor repair manaul Let me know what you find out. John [email protected].

Paul, Its important that BOTH the Generator and Voltage Regulator have a good ground. Maybe run a good ground jumper to the genny AND the Voltage Regulators metallic case n see what happens.

If you put a volt meter on the battery it should read around 12.6 volts setting, but once runnign at fast RPM IFFFFFFFFF the genny is working it should rise to around 13 to maybe 14 volt range.

As posted below YES when shes running if you dead ground the gennys FLD post she should max charge sooooooooo if it charges (battery voltage rises) when you do that but NOT OTHERWISE, the problem is EITHER the VR is bad orrrrrrrrr the VR doesnt have a good ground orrrrrrr the wires open from the FLD post on Genny to FLD terminal on VR.

If theres still no charge even with FLD post dead groudeed when shes running, leave it grounded then by pass jump the VR's Cutout Relay by momentarily connecting its its BAT terminal to its ARM/GEN terminal n see if she charges then. If so but NOT OTHERWISE, THE vr'S INTERNAL CUTOUT RELAY IS BAD.

With thE gennys FLD post dead grounded AND the cutout realy by passed (GEN/ARM junmepd to BAT) the VR is essentialy by passed and out of the equation so if still no charge the genny (or other necessary wiring etc) is the problem.

Let us know

John T

Use a volt meter to check the voltage on the A terminal with engine at about 1/2 throttle. Should see about 14 volts. I would clean the terminals on the regulator before replacing it.

I have the same setup on my garden tractor, but it has the B&S engine. I was only getting about 13 volts at the battery terminals. Thought it was the regulator too. When removing the battery I noticed the postive battery cable had a bare spot from rubbing against the sheet metal. I covered the bare spot with electrical tape. That fixed the problem. The generator never had the brushes replaced, I pulled the generator and removed the end cover. The brushes were almost
worn out. I had a shop to replace the bearings and brushes and they trued the commutator too.
Cost about $50.00. Voltage at the battery is now
14.5 volts. Can't complain after being in use 37 years. Hal

Is this on a Cub Cadet? The CC guys will tell you that they are notorious for bad grounds as others have said...Grounding the field will make it charge full bore provided the gen is ok.

I replied earlier about testing you generator with test light. I forgot to mention that all this is doing it creating an idiot light. You will have to rev the engine for the generator to put out. That was the down fall on the ole generators. One other down fall was like the one guy mentioned every thing has to have a good ground when a generator is used. I've actually put a jumper wire from the generator case the to regulator case to the battery ground terminal. Eleminate any doubt with in the circuit. They make new electronic regulators for the ole generators that work very well.